Overdrive or Regular?

Should I buy a regular 4 speed or an overdrive?
$250 for the overdrive and $350 for the regular.

Depends on how original you want to be and what you're using the car for, and what rear end gears you're running

both my Bee and my Challenger have the standard original 833 and 3.55 gears, I wouldn't trade for an overdrive for the short trips and knocking around I do. if I lived where I drove on the freeways and or had 3.91 or lower gears I'd consider it. well I might, it was never an option and I'm an originality freak so I probably wouldn't.

The spacing of the ratios in the OD make it a bit harder to "bang gears"

I also hear that the aluminum case overdrive trannys won't take as much abuse/ horsepower as an iron case 833. Something else to think about...

yeah, I'm not really an OEM freak so thats not an issue.
I wanna get 3.55 gears for the rear end so I guess I'll go with the regular 4 speed

The biggest "problem" with the aluminum cases is where the counter cluster shaft fits in the case. IF you go banging on it, it's possible to wallow out the case there. BUT, Passion Performance makes a bushing to go in there. It requires some machining on the case, but if you want the OD, it's money well spent.

And btw, if you have a regular 4 speed with 3.55's, you'll have 3.55's. But if you run 3.91's with the OD you'll have a 2.85

The OD 4-speed is an awesome swap... I swapped one into my boss's Superbird for driving to shows and such.... It is a six pack 4-speed trac pack car so it has a 3.54 dana... with the OD I went from Los Angeles to San Diego and back averaging 27 mpg.

The weak link in the aluminum case 4-speed is as stated above there is a .005 (i think) clearance between the countershaft and the case... if you bush this I have seen a guy run one behind a blown 440 with 15" Mickey T's without issues.

My opinion - unless you go racing with the car the OD is a great addition...

I've read about the Passon conversions. You end up with a strong 4-speed but still wide spaces between the gears. I have a Keisler 5-spd conversion using a Tremec TKO 5-spd. It has a steeper first gear than the stock 833 so my 3.54s in the Dana launch like a stock tranny and 4.11s. Overdrive is .68 so it top gear is like having 2.70s or such. They are now a no-cut, no-weld bolt-in. Not cheap, but another option.

Beware - the Keisler kit gives a horrible pinion angle from what i've seen... Awesome transmission though - I got mine through Darkhorse performance and fabbed my own crossmember to give a better pinion angle.

I've read about the Passon conversions. You end up with a strong 4-speed but still wide spaces between the gears. I have a Keisler 5-spd conversion using a Tremec TKO 5-spd. It has a steeper first gear than the stock 833 so my 3.54s in the Dana launch like a stock tranny and 4.11s. Overdrive is .68 so it top gear is like having 2.70s or such. They are now a no-cut, no-weld bolt-in. Not cheap, but another option.


Don't forget to mention how you sort of convulsed like you'd been hit with a defib when I drove the car that first time and snap shifted second gear.:grin:

I've read about the Passon conversions. You end up with a strong 4-speed but still wide spaces between the gears. I have a Keisler 5-spd conversion using a Tremec TKO 5-spd. It has a steeper first gear than the stock 833 so my 3.54s in the Dana launch like a stock tranny and 4.11s. Overdrive is .68 so it top gear is like having 2.70s or such. They are now a no-cut, no-weld bolt-in. Not cheap, but another option.

I some day PLAN to buy a Passon overdrive unit. I don't think the gear spread is bad at all. It is basically the same as an automatic in the first three gears. I have a 4:56.1 rear and plan to run the 1/4 in three gears.

why run the passon kit ? bush the stock OD trans and run it hard... i know guys running in the 10's with them

how do you think the OD would hold up behind a 440?
cause i just found a running 440 from a motor home for $400!

It has a 23 spline input shaft. And if you run sticky tires it's possible to twist that shaft. I know. It was done with Greg's car before he bought it.

nah nah, i'm gonna run some regular street tires I have no intentions on bringing this thing to the track I think I saw on passion performance like a conversion from 23 to 18 spline??
i dunno i may be crazy.

They might have an 18 spline shaft with the correct gear on it for the OD. I don't know. Some racers will also gut their Hemi trans and build it in an aluminum case to save weight. Hence 18 spline aluminum trans...

yeah true true.
my original intention was to put the OD behind a worked over 318 making maybe 400 horses? probably more like 350-375 but anyways I dunno i'm still deciding what to do.
that 440 is looking better and better...

why run the passon kit ? bush the stock OD trans and run it hard... i know guys running in the 10's with them

You should probably go to Passon's web site for ALL of the answers. For me it is a combination of things.

1. No floor or ther drivetrain modifications.

2. Looks totally stock.

3. Has the H.D. Hemi shaft and gears.

4. Has an OD 4th gear that will allow me to drive this car on the highway with 4:56.1 gears at a reasonable RPM.

5. Can be purchased as a gear set to be installed in MY trans case.

6. Gear spread allows me to run the 1/4 in three gears.

You should probably go to Passon's web site for ALL of the answers. For me it is a combination of things.

1. No floor or ther drivetrain modifications.

2. Looks totally stock.

3. Has the H.D. Hemi shaft and gears.

4. Has an OD 4th gear that will allow me to drive this car on the highway with 4:56.1 gears at a reasonable RPM.

5. Can be purchased as a gear set to be installed in MY trans case.

6. Gear spread allows me to run the 1/4 in three gears.


Granted... however the Passon kit is a "copy" of the factory OD transmission but with 18 splines... other than that there is no difference... if you're not drag racing it you'll be alright....

how will it hold up to a 440 ? my old boss had one behind a blown 440 (est. 750hp) and 15" Micky thompsons without issue... The one in my boss's superbird's transmission has held up behind the six pack for years and I honestly am very hard on that car... it has gone around willow springs raceway and gone down the 1/4 mile numerous times with slicks... no issue... and remember it bolts right in too....

I know what the Passon kit is... Car Craft did an article of our shop installing this kit into a 4-speed.... but i dont think it is needed for your application.

Granted... however the Passon kit is a "copy" of the factory OD transmission but with 18 splines... other than that there is no difference... if you're not drag racing it you'll be alright....

how will it hold up to a 440 ? my old boss had one behind a blown 440 (est. 750hp) and 15" Micky thompsons without issue... The one in my boss's superbird's transmission has held up behind the six pack for years and I honestly am very hard on that car... it has gone around willow springs raceway and gone down the 1/4 mile numerous times with slicks... no issue... and remember it bolts right in too....

I know what the Passon kit is... Car Craft did an article of our shop installing this kit into a 4-speed.... but i dont think it is needed for your application.


You are WAY off with that statement. You need to check the gear spread between the two, AND the ENTIRE gear set is Hemi H.D. not just the input shaft. I make it real simple for you, go here: http://www.passonperformance.com/NewProducts/Passon%20Overdrive%20Flyer.pdf

The old factory OD unit was built for /6 and 318 applications. It is my understanding from reading MANY posts about it on Moparts, that it will not hold up for racing behind a big block and that the gear spread is NOT 1/4 mile friendly. You go right on ahead and use it, but your not talking me into it.

So dont do the van OD... spend the $$$ on the passon kit.

Seems the guys on Moparts dont know how to build transmissions... Go over to the Dodge Charger and ask Chryco Psycho about them... he'll say he uses them all the time for drag racing without problems...

So dont do the van OD... spend the $$$ on the passon kit.
Seems the guys on Moparts dont know how to build transmissions... Go over to the Dodge Charger and ask Chryco Psycho about them... he'll say he uses them all the time for drag racing without problems...


I plan on it.

What you or others do is your business.

I think the info in the link I provided to Passon's OD unit pretty clearly spells out the strength AND the gear spread differences which are HUGH.

I don't care who rebuilds your trans, it is not going to increase the gear set or input shaft strength. The gear spread of the old OD unit is horrible for any kind of racing.

The old OD transmission is a poor mans answer for better mileage/reduce engine RPMs at highway speeds. Anyone using it in a real high performance application is just asking for problem and will eventually see them with that trans and any kind of hard shifting. If you want to coddle your car It will be fine, but that doesn't sound like the typical situation here.

This convo has swayed from the original topic - I was simply stating to 69charger that for his application the OD transmission would be fine as he does not plan on racing...


I understand Passon says their kit is amazing... I admit i was incorrect with what i said about it being a copy of the factory OD stuff... I just don't see the point in dropping close to $3K when a well built factory OD will fit the bill for his application -

I have never seen personally the "weakness" of the factory OD transmission - never seen a shaft snap nor a twisted input... I am not saying this has never happened - just I have never seen it in the numerous cars I have done this swap in... The only thing I have seen is the cracking problem between the countershaft hole and the main shaft holes... which is a result from the loose tolerance from the factory... I always use a bushing which eliminates this problem.... No problems after that...

The gear ratios are different (already stated I was incorrect on this topic before) - I believe the typical big block making gobs of torque overs the splits quite easily - but I'll be the first to admit I'd rather lose a tenth at the track and save $$$ and go cruising -

Again - I was wrong - I didn't mean to stir up anything - I was simply stating for 69charger "why go with the passon kit?" when the factory OD would be alright for his application.

Why screw around with that junk, just get a good trans ..:grin:

magnesium case has an extra gear AND is a WHOLE lot stronger than the old iron pigs.

PS it shifts a tad faster and more solidly also...

I'm a fan of the Tremec transmissions myself... internal rail shifting rocks... We installed a Richmond gear transmission into the Car Craft Rambler and had quite a few issues - but now that it is in it runs great

Not everyone wants (or can) spend the kind of money it takes for a fat trans like that. They may not want that shifter protruding through their floor looking like it only belongs in a Pro Stock car instead of a factory hot rod.

Guess those folk PLANed on something else:edgy:



Why screw around with that junk, just get a good trans ..:grin:

magnesium case has an extra gear AND is a WHOLE lot stronger than the old iron pigs.

PS it shifts a tad faster and more solidly also...

Not everyone wants (or can) spend the kind of money it takes for a fat trans like that. They may not want that shifter protruding through their floor looking like it only belongs in a Pro Stock car instead of a factory hot rod.

Guess those folk PLANed on something else:edgy:

I agree.

I don't like the idea of spending the kind of money that Passon gets for his OD unit either, but it is the least expensive and least invasive to the car in terms of floor modifications. The Tremac while a better trans in terms of gear spread in the 1-4 is the best performance wise as well as a better OD gear, it is also the most invasive to the car in terms of floor modifications and the most expensive.

The Passon unit is the next best thing with regards to 1-3 gear spread and the OD gear, but absolutely no modifications to the car and less expensive.

The old /6-318 light duty OD unit is on the bottom of my buy list simply because the have a lousy gear spread and the inherent weakness of the trans. Yes, they are cheap, but that is because they are not very sought after. Also they are only cheap if you can use it as-is and don't have to rebuild it. If you have to rebuild it the rebuild cost is pretty much the same as rebuilding any 833, so why not apply the purchase and rebuild price to the cost of a Passon unit?

There are trade offs with all of them, there is no perfect senerio here. It depends on what an indiviual can live with and how much abuse you are going to give it and what you are willing to chance for damage.

I just picked up one of these aluminum OD units with the possibility of using it in my 69 RR with a 440 six pac. Some of the things I've been thinking about regarding the possible use of this trans in my car:

The gear ratios are not suited for any kind of narrow power band performance tuned engine, so cam selection is limited. The stock six pac intake may limit cam selection too so I'm sure something similar to a magnum cam would be best. I think a big flat torque curve is king with this tranny. Any of you ever driven a VW bug??

Replace the aluminum case with a cast one. The weight savings between the two on 3700 lbs of rolling stock is like peeing in the ocean. I'd rather have the durability.

Not too worried about the 23 spline. We ran plenty of those back in the 80's behind 440's in our street cars and beat the snot out of them. Adding slicks may be a different story, but on street tires the tires are the fuse.

Hey 69 I PLANNED on it not to BREAK..glad you mentioned that, very important, thanks.... :grin:

One 3500 NOS PRO trans from a cancelled project vrs 3-4 833s costing 1200 1800 each w/slick or pro shifterd gears to have as spares when the 2 to 3 shift grenaded the trans..( PS I sold those 833s to Jamie....drove up and unloaded them directly into his garage...)

In my case it was CHEAPER to go PRO...:yes:

By "Modifing" the trans tunnel and the crossmembers for the trans, made it a whole lot easier to service the trans and shifter from inside the car, made shifting ROCK solid, and was really neat..as an added benefits..

See there is more than one way to skin any cat.....:HappyNewYear:

I also hear that the aluminum case overdrive trannys won't take as much abuse/ horsepower as an iron case 833. Something else to think about...

First, a bit of background. My business offers up a ton of race built modern 5-speeds and 6-speeds for almost any Big3 powered ride, so I have lots of experience with OD transmissions. I am not trying to sell anyone anything, but I have seen plenty of smoking piles of parts to give a good opinion here.

I've got TKO 5-speeds with aluminum cases in cars with 900+ ft-lbs of torque running for a couple of years now without breaking the transmission. A webbed aluminum case will take a lot more shock load than a smooth casting. You can always throw a girdle on your aluminum 4-speed or 5-speed to keep the case from ballooning and spreading the shafts apart, a major reason for transmission death. Keep in mind that the overdrive gear is inherently the weakest gear, and the metallurgy that existed when the OE A833 4-speeds were built make them a pretty weak trans. The Passon OD 4-speed is very strong, reason being is they build their OD shafts and gears with the best technology available today. (I don't sell Passon, but they do make good transmissions). They only rub on the 4-speed OD transmissions is that the gaps between gear ratios are huge and there is not much OD. You just can't split ratios 4-ways and get a better result than splitting them 5-ways.

Also, running a little slip in the clutch or a fully sprung disc hub will go a long way to preserving the transmission. Solid hub clutches and street-twins with no slip are absolute murder on a transmission.

Hope all of this helps. AP

First, a bit of background. My business offers up a ton of race built modern 5-speeds and 6-speeds for almost any Big3 powered ride, so I have lots of experience with OD transmissions. I am not trying to sell anyone anything, but I have seen plenty of smoking piles of parts to give a good opinion here.

I've got TKO 5-speeds with aluminum cases in cars with 900+ ft-lbs of torque running for a couple of years now without breaking the transmission. A webbed aluminum case will take a lot more shock load than a smooth casting. You can always throw a girdle on your aluminum 4-speed or 5-speed to keep the case from ballooning and spreading the shafts apart, a major reason for transmission death. Keep in mind that the overdrive gear is inherently the weakest gear, and the metallurgy that existed when the OE A833 4-speeds were built make them a pretty weak trans. The Passon OD 4-speed is very strong, reason being is they build their OD shafts and gears with the best technology available today. (I don't sell Passon, but they do make good transmissions). They only rub on the 4-speed OD transmissions is that the gaps between gear ratios are huge and there is not much OD. You just can't split ratios 4-ways and get a better result than splitting them 5-ways.

Also, running a little slip in the clutch or a fully sprung disc hub will go a long way to preserving the transmission. Solid hub clutches and street-twins with no slip are absolute murder on a transmission.

Hope all of this helps. AP


I assume that in the bolded area you are speaking of the original Mopar built aluminum case 4 speed OD unit and NOT the Passon unit?

I assume that in the bolded area you are speaking of the original Mopar built aluminum case 4 speed OD unit and NOT the Passon unit?

Well, actually I was speaking in general. Let me say that I have the utmost respect for Passon and its products. They make some very, very fine transmissions and parts. That being said, the way a car performs based on gear ratios is not a question of quality but rather a question of physics.

If you look at the gear ratios of the Passon OD 4-speed you have a drop from a 2.66 1st to a 1.59 2nd gear, and 3rd is 1:1, for a 1.59 drop. These are pretty significant gaps. Generally speaking it is easy for the car to live with a long drop 1st to 2nd because once you have overcome the lack of inertia at a dead stop, the 2nd gear does not have as much work to do. A 2 to 3 drop is a little harder to take and a 1.59 drop into third is going to cause a lot of engines to fall on their face, especially given the curb weight of a B-body. In addition, the .80 overdrive gear only reduces the rpms by 20%, which does not knock the revs down as much as most guys are looking for. So you have big gaps where performance should be enhanced and a small gap where you should be cruising at low RPMs. This is not necessarily a deal breaker, but it is certainly not ideal either, especially considering that there are alternatives.

If you look at the TKO600, by comparison, the ratios are 2.87, 1.89, 1.28 and 1:1 with a choice of .82 OD for road racing and really agressive cams, and the much more popular .64 OD for cruising. You can see that the gap from 1 to 2 is still fairly significant, but as you move through the gears the gaps tighten up, ideal for performance. The TKO500 is often passed over because the drop from 1 to 2 is from 3.27 to 1.98, which lugs a lot of engines on the 1 to 2 shift. The TKO500 is handy for cars with tall rear gears (3.08, 3.23) and high revving small blocks that need quick RPM build to get to the power band quickly.

Admittedly, the biggest advantage the Passon has is that it fits just like the original transmission, which makes installation a snap. The TKO, on the the other hand it massively durable and has better ratios for the job. Five gears simply make it easier to split up the gear ratios for more performance advantage.

Hope I did not answer that one to death. :grin: AP

Well, actually I was speaking in general. Let me say that I have the utmost respect for Passon and its products. They make some very, very fine transmissions and parts. That being said, the way a car performs based on gear ratios is not a question of quality but rather a question of physics.

If you look at the gear ratios of the Passon OD 4-speed you have a drop from a 2.66 1st to a 1.59 2nd gear, and 3rd is 1:1, for a 1.59 drop. These are pretty significant gaps. Generally speaking it is easy for the car to live with a long drop 1st to 2nd because once you have overcome the lack of inertia at a dead stop, the 2nd gear does not have as much work to do. A 2 to 3 drop is a little harder to take and a 1.59 drop into third is going to cause a lot of engines to fall on their face, especially given the curb weight of a B-body. In addition, the .80 overdrive gear only reduces the rpms by 20%, which does not knock the revs down as much as most guys are looking for. So you have big gaps where performance should be enhanced and a small gap where you should be cruising at low RPMs. This is not necessarily a deal breaker, but it is certainly not ideal either, especially considering that there are alternatives.

If you look at the TKO600, by comparison, the ratios are 2.87, 1.89, 1.28 and 1:1 with a choice of .82 OD for road racing and really agressive cams, and the much more popular .64 OD for cruising. You can see that the gap from 1 to 2 is still fairly significant, but as you move through the gears the gaps tighten up, ideal for performance. The TKO500 is often passed over because the drop from 1 to 2 is from 3.27 to 1.98, which lugs a lot of engines on the 1 to 2 shift. The TKO500 is handy for cars with tall rear gears (3.08, 3.23) and high revving small blocks that need quick RPM build to get to the power band quickly.

Admittedly, the biggest advantage the Passon has is that it fits just like the original transmission, which makes installation a snap. The TKO, on the the other hand it massively durable and has better ratios for the job. Five gears simply make it easier to split up the gear ratios for more performance advantage.
Hope I did not answer that one to death. :grin: AP


Yes, I agree, however the Passon overdrive units first 3 gears are nearly identical to a 727 auto trans 3 gears. The auto trans shifts faster than the average man can shift a manual and is faster in the 1/4 mile in the same car. I don't think the gear spread is any kind of disadvantage for racing due to this. You run the quarter in 3 manual gears rather than 4 with Passon's OD trans so it is one less manual SLOW shift when comparing 1/4 mile times between the auto and manual car.

America power most these guys are auto guys and have a hard time understanding that keeping an engine in its power band, through the proper gear spreads, is real important in racing..and everyday driving...an 833 and 727 are compromises..

Mine is 2.62 first to 1:1 5th... as equal gear spread as Leo (GForce) makes...I adjust up and down with the rear tire diameter and ratio.. makes for a snappy drive...:grin:

America power most these guys are auto guys and have a hard time understanding that keeping an engine in its power band, through the proper gear spreads, is real important in racing..and everyday driving...an 833 and 727 are compromises..

Mine is 2.62 first to 1:1 5th... as equal gear spread as Leo (GForce) makes...I adjust up and down with the rear tire diameter and ratio.. makes for a snappy drive...:grin:

I AM a 4 speed guy, and I do understand keeping an engine in the power band. The only auto muscle car I have had in the last 20 years is my LRET. Passon's OD trans gear spread is as follows:
Stock Overdrive
1st 2.65 : 1 2.66 : 1
2nd 1.93 : 1 1.59 : 1
3rd 1.39 : 1 1.00 : 1
4th 1.00 : 1 .80 : 1

I don't see any big problem with this gear spread.

As I said in an earlier post, ALL the choices have compromises. The PASSON unit is the best for ME. I don't want to cut my floor pan and have a not factory type shifter that draws attention to the trans. I want to be able to drive my 6 pack Bee on the freeway for 2 hours at a time without running at excessive RPMs. I have 4:56 gears and will be pushing it even with this OD unit. In fact, the 4;56s may be too steep for the 1/4 in 3 gears and I MAY have to go back to the 4;10s. I think it is right for me for what I want out of my car, but that doesn't mean it is right for others.

My car will be an occassional street driver and an occassional drag car that should run in the low to mid 11s and that is all I want out of it. I don't want it to be an unstreetable car AND I will be running A/C, P.S. and P.B.

I just don't think the Passon OD can be COMPARED to the original old Mopar OD unit with it's VERY wide gear ratio spread.

Interesting how Passon talks about the weakness of the O.E. O.D., but then compares their O.D. to a regular 4 speed's ratios.

Anyone know what the ratios of the O.E. O.D are? Isn't "4th" a .73 compared to Passon's .80?

3.09:1 - 1.67:1 - 1:1 - 0.73:1

There is 1-4 in the factory OD... yes i know that 3rd is the OD gear but this is the pattern than the driver shifts into so for the sake of argument just accept this as truth...

in all honesty - the factory OD is great for a street car where ideal performance is not a huge deal - yes the first gear is a bit steeper than the Passon kit but you also get what ? 27% engine rpm reduction on the other end ? Works for my street cars...

3.09:1 - 1.67:1 - 1:1 - 0.73:1

There is 1-4 in the factory OD... yes i know that 3rd is the OD gear but this is the pattern than the driver shifts into so for the sake of argument just accept this as truth...

in all honesty - the factory OD is great for a street car where ideal performance is not a huge deal - yes the first gear is a bit steeper than the Passon kit but you also get what ? 27% engine rpm reduction on the other end ? Works for my street cars...


What kind of hp are you running in your street car?

I have an iron case o.d. for my Dart. Time will tell if I like it or not but I wanted a car I can drive just about any were for a change.

Interesting how Passon talks about the weakness of the O.E. O.D., but then compares their O.D. to a regular 4 speed's ratios.

Anyone know what the ratios of the O.E. O.D are? Isn't "4th" a .73 compared to Passon's .80?

The reason they make this claim is that the gear cutting and quality of currently available alloys give them a significant edge in strength over the original equipment OD. As I said in an earlier post, the OD versions of any of the older transmissions from the Big3 were suspect because the OD gear is inherently the weakest gear, there is more torque multiplication in OD and the alloys available back in the day were not nearly what they are today. That's why you don't see high torque muscle cars that came stock with factory OD, because a lot of the stock engines would have toasted them. Again, that does not make them bad transmissions, it just makes them comparably weak when you consider the non-OD versions.

What kind of hp are you running in your street car?

safe HP lol I've put them behind engines making anywhere from a stock 375 to somewhere around the 650 range -

I spoke with Jamie Passon at SEMA a few days ago. Wow, what a straight-up guy. My company competes with Passon since we sell TKO kits for Mopars, but I have to say that I have rarely met anyone in the aftermarket business who treats people with as much respect and honesty as Mr. Passon. If you guys are considering a Passon transmission, you can feel confident that you will get the straight scoop from them. If you are looking to do a TKO, call us. :yes:

Well, since this thread is still alive and has somewhat run off track from the original poster's question, I will direct those interested tp this Moparts thread.

Here is a copy and paste from one poster there regarding this, but I also encourage people to read ALL of the peoples posts that have purchased both the Passon and Keisler O.D. units.

Having driven several Kielser equipped cars and a couple Passon trans cars, here's my .02.

1. For a true "no hack" install the nod CLEARLY goes to Passon
2. If you drag race you'll like the Passon, the Kielser is not a fast shifting trans, a bit too sluggish and notchy, especially at higher RPMs
3. If you want the strongest trans, Passons will take more HP than a Kielser by a fair margin
4. For cost and ease of install, Passon wins
5. For the best highway crusing O/D situation, Keisler wins due to it's better high gear ratio
6. Fuel milage Kielser also wins, same reason
7. Service - Passon hands down
8. With a 3:54 geared car that you do not want to modify beyond clean/simple easily reversable bolt ons and is mainly street driven and occasionally drag raced - Passon
9. For a modified car that is mainly used for local car shows, street cruising, taken on a good many long highway runs and not much else - Kielser
10. If considering these two companies you should also look into Gear Vendors and Classic 5 Speed before buying, may as well see what everyone is selling before you pull the trigger. I have also driven Gear vendor equipped cars, they should be a consideration for sure, they make a good product.

Here is the link to the entire Moparts thread:

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=4787748&an=0&page=1#Post4787748

1. For a true "no hack" install the nod CLEARLY goes to Passon TRUE
2. If you drag race you'll like the Passon, the Kielser is not a fast shifting trans, a bit too sluggish and notchy, especially at higher RPMs I disagree. Up to about 6200rpm the Tremec TKO (Keisler does not make any transmissions) can be speed shifted. You may have driven a few older TKOs that did not have micro-finished lugs, which made the 2-3 shift a chore. Also, if you are using a Keisler hydraulic system you may be getting clutch drag, which limits high rpm shifting. I would at least give the two a tie.
3. If you want the strongest trans, Passons will take more HP than a Kielser by a fair margin Not true at all. Static torque testing at Tremec proved the TKO600 up to 1400ft-lbs of static torque. I have sold over 2600 TKO transmissions and have only two failures under load. That is a solid track record from personal experience.
4. For cost and ease of install, Passon wins Can't argue with that!:)
5. For the best highway crusing O/D situation, Keisler wins due to it's better high gear ratio Agreed
6. Fuel milage Kielser also wins, same reason Again, I agree that the Tremec wins, but Classic, American Powertrain (taking a bow) and Keisler all base kits on Tremec TKOs.
7. Service - Passon hands down Check out Classic or AP for much better customer service than Keisler. We even have a 24-hour tech line. Passon gives great service too.
8. With a 3:54 geared car that you do not want to modify beyond clean/simple easily reversable bolt ons and is mainly street driven and occasionally drag raced - Passon Yep, OK
9. For a modified car that is mainly used for local car shows, street cruising, taken on a good many long highway runs and not much else - We can mod the TKO to take 11,000 rpm shifts if that is what you are into. Keisler used to be the only player, but not anymore!
10. If considering these two companies you should also look into Gear Vendors and Classic 5 Speed before buying, may as well see what everyone is selling before you pull the trigger. I have also driven Gear vendor equipped cars, they should be a consideration for sure, they make a good product. I feel so abused. Not even a mention of American Powertrain. Ya'll don't know what you're missing. :edgy:

Here is the link to the entire Moparts thread:

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=4787748&an=0&page=1#Post4787748[/QUOTE]

By service do you mean service on the transmission or customer service ? If you mean transmission service then I have to disagree... The TKO is a widely used transmission with parts availability where as the Passon kit has only one source for parts... i hate only having one option but that's only me...

By service do you mean service on the transmission or customer service ? If you mean transmission service then I have to disagree... The TKO is a widely used transmission with parts availability where as the Passon kit has only one source for parts... i hate only having one option but that's only me...

When I mentioned service in my post I was referring to reactivity to customer needs. We have a 24-hour tech line, available on nights, weekends and holidays when many DIY guys are under their cars. We stock almost everything you might need if you bugger up a part, or need a set of dowel pins to line up your bell housing. We also know what we are talking about, a real plus when you need tech help. Most issues can be solved in just a few minutes.

24-hour availability and the knowledge to help when needed is the best we can offer, so we do! :grin:

To give Passon their props, they are very reactive and will give you the straight scoop whenever they are available. As far as parts availability, you certainly would not expect Passon to have the same parts pipeline as a huge company like Tremec, so I suppose by your definition we Tremec guys get the nod, but not for lack of trying on the part of Passon.

Here is an interesting comment by Jamie Passon regarding the somewhat heated discussion on the thread over at Moparts.

Gene,
Thanks for the invite. I do appreciate it. However, the last time I did that it only got me into a HUGE "discussion" on this board that ended up getting the post locked and started a whole bunch of hard feelings. So, that being said, thank you, but I thought it better to not bother you guys. If I remember, wasn't there a guy there anyway? I didn't want to interrupt you.

Now to some math:

Here is my biggest problem with you guys saying that the ratios in our trans are so wide.

1st to 2nd gear change is 1.07 in our unit. It is 1.00 in yours. Maybe I am out in left field, but I really don't call that tremendously different.

2nd to third gear change is .59 in our unit. It is .61 in your unit. So, you are actually wider there. Again, I am not going to say that you are tremendously wide either. But in fairness, I never claimed that you were.

3rd to 4th is .20 in our unit and .28 in yours. AGAIN, WIDER!!!!!!

Yes, you have a 4th to 5th gear shift. However, when talking ratios, that is not relevant.

In my opinion, the ONLY thing that you guys have over us is a taller OD. Which is fine, however, it seems to me that strength might be compromised by doing this. That is why we didn't make a steeper OD. We were concerned about making the stongest unit we could. Regardless, I have not personally had ANYONE call me complaining that the OD was not enough.

Now, I know the story of the transmission fixture breaking at 1400 lb/ft of torque, but lets be serious, if this were the case, a tremec trans would be virtually IMPOSSIBLE to break. I think that we both know that his isn't the case. I find it wierd that if they can take 1400 lb/ft of torque, then why are they rated at LESS THAN HALF of that number???? I know this, If my unit could take 1400 lb/ft of torque, I sure as heck would not rate it at less than half of its capabilites.

By the same token, I am not saying that one of our units is unbreakable. BUT, I am quite confident that it will take more than 600 lb of torque.


Lets look at another aspect here.

Howabout how steep your 1st gear is?

The final drive ratio in each gear is calculated by multiplying the transmission gear ratio by the rear end ratio. I picked a generic ratio that is a good rear ratio in a car that is a candidate for an overdrive. So, lets do some more math.

Your first gear: 2.89 X 4.10 = 11.84 final drive
Our first gear: 2.66 X 4.10 = 10.90 final drive

That is a .94 difference. The way that you guys talk about how crappy our ratios are, this is a MONUMENTAL difference in gear ratios. No wonder why no one mentions it. So, why isn't anyone pointing this out??????? It seems like a relevant point to me.

Let me also say, there is not personal attack here at all. It is simple math. I am just amazed at how you guys "gloss over" the tremec's shortcomings and point out that our unit has such a horribly wide gear spread. The fact is: IT DOESN'T.

Jamie

(Keisler does not make any transmissions)

You are right Gray, we do not make transmisisons, we make them better.

I have to argue a bit on the customer support comments about Keisler. I have had mine for over five years. I had no problems with the tranny AT ALL. Their tech people have always helped me quickly. I had issues this summer with the hydraulic clutch kit, but even though I waited two years between the purchase and actually installing it they have supported me. My clutch didn't disengage very well - they sent me the latest slave cylinder and hydraulic line at no charge. I had some firewall flexing - they sent me a brace at no charge.

I have to argue a bit on the customer support comments about Keisler. I have had mine for over five years. I had no problems with the tranny AT ALL. Their tech people have always helped me quickly. I had issues this summer with the hydraulic clutch kit, but even though I waited two years between the purchase and actually installing it they have supported me. My clutch didn't disengage very well - they sent me the latest slave cylinder and hydraulic line at no charge. I had some firewall flexing - they sent me a brace at no charge.

Every company has it's successes, and I would certainly not say that the biggest seller of Mopar TKO kits did not have some great things going for it. That does not mean, however, that there are not companies out there doing a better job. I am happy to hear you had a great experience. As evidenced by posts on some of the bigger forums, and my four years working for them, there are many who have not.

I agree. The biggest or the first may not be the best. I welcome American Powertrain to the Mopar aftermarket. I subscribe to a Mopar-specific magazine and two all-brand hot rod-type magazines and haven't seen your ads, didn't know about you until I saw you on this forum. My bad!

The only thing needed as stated is to bush the case. When the case holes get to big it cocks the input shaft putting it in a bind with the clutch. That's the only way your going to twist the shaft. I've bent and twisted 18 and 23 splines both. But set up right mopar inputs shafts don't bend or twist. The wives tales about the OD trans and the 81/4 rear end are just that. Wives tales ether one is an almost forever piece if set up right.

The 23 spline input shaft that got twisted in Greg's car by the P.O. was in a steel case. Was a case of lots of weight, lots of torque, and lots of traction colliding all at once

I agree. The biggest or the first may not be the best. I welcome American Powertrain to the Mopar aftermarket. I subscribe to a Mopar-specific magazine and two all-brand hot rod-type magazines and haven't seen your ads, didn't know about you until I saw you on this forum. My bad!

Thanks for the welcome. We are relatively small compared to Keisler and we spend most of our marketing budget online and on our website. We also go to quite a few live shows.

Sorry for the off topic everyone. Back to the subject at hand. :grin: