Overdrive tranny choices

[dcmason69]

Looking to add O/D tranny to 69 coronet 440, I do not want to modify tunnel or go with gear venders. Has anyone done or know someone who has put a 4L60E tranny conversion kit in from Silver Sport transmissions. They are pricy but only require slight modification of pinch weld lip at firewall floorpan area for bolt clearance. I know and I hate the fact that this is a GM tranny but looks like my options are few. Open for comment or suggestions.
Thanks dcmason69

 

[Bad B-rad]

I have fit a 46RE in a 1973 Ebody, with only a few blow of the hammer on the tunnel, and some slight grinding on transmission case.(needed a custom made trans mount with a 700r4 rubber)
But no cutting the tunnel, or Torsion bar X member.
I DO NOT KNOW if it would be the same on a B body.
Also my Challenger had a 5.9 Magnum in it, not a 440, so I realize the trans would have to be build to handle your 440's power level.

I have read about a lot of guys running truck 518's, I think its almost the same as a 46RE.
For me I cant afford a $8,500 transmission so I had to go with a less expensive option.

I also look forward to reading responses to your question.

 

[wish4hemi]

What is the problem with Gear Vendors? It effectively turns your 904 or 727 into a six-speed automatic with dramatically better ratio spreads than a 4L60E, especially with the 4L60E's massive, crappy dump between first and second. Torque multiplication is hugely important in the lower gears, so I wouldn't give it up just for an overdrive gear on top. You get to keep the Chrysler transmission, have more gear ratios available, and I believe it's cheaper than the SST A41. https://www.gearvendors.com/hrdodge3s.html

But, if you are still leaning SST A41, here is an installation article: https://moparconnectionmagazine.com...smissions-a41-perfectfit-overdrive-automatic/

 

[vance.dykes]

put a 518 mopar in it . check on google it out there.https://transmissioncenter.net/shop/727-to-518-transmission-swap-information/

 

[Bad B-rad]

Personally, I like the gear vendors, option.
I have only read of one semi common complaint, with the GV unit, and it was the drive line angle change.
I must admit, it has been 15+ years last time I did any homework on the Gear Vendors unit, and this may have been fixed by now.
I know they are STRONG!!!

 

[F4R/T]

Me personally I wouldn’t waste my time with a GM trans, I personally prefer the Mopar Route, yes you will have to spruce it up but you will have to spruce up the 4L80 which is a glorified door stop. And the nice thing is there are plenty of options with the mopar OD route you may need to make a few extra contacts but they are there from gear sets to converters ... or go gear-vendors route... it’s your car and your coin the cheapest is the probably the GM trans.... but tell a mopar guy you have a Chevy tranny is like putting a 9” rear diff when you should have went to a Dana 60– just my opinion as I’ve replaced many GM trannies they are no better or worse than anything else and the only thing they have going is cost and physical size...

 

[diesel_lv]

Personally, I like the gear vendors, option.
I have only read of one semi common complaint, with the GV unit, and it was the drive line angle change.
I must admit, it has been 15+ years last time I did any homework on the Gear Vendors unit, and this may have been fixed by now.
I know they are STRONG!!!

Not changed, just put one in 2 months ago in 1967 Coronet. Where the flanged on the o/d unit and the tail shaft adapter meet, the trans tunnel needs to be hammered about 3/4 of an inch the entire way around. Then the area where they actually say you "may" need to dimple, needs some serious "dimpling". With the clearancing on the transmission crossmember that they require, my engine sits down 2°, rear diff is down 1°, driveshaft is down 3°. All within tolerance but not sure how it will be when I get on it.

 

[Bad B-rad]

I had no idea about the hammer work to tunnel, just about drive line angle issues.

Some guys say that all gets forgotten when you hear your engine shifting 5 times, under wot!!!

Good luck with yours, DIESEL_LV!!!!


From my current reading, looks like 518 is VERY popular now.

My 1973 Challenger with 46RE is one of the first to pop up on Google, but in text only, photos are gone, and it was way back in 2009, LOL!!!

 

[65affair]

There is a lot of good talking points and is a very interesting thread, my two cents, I'm not a fan of mixing brands but I know a lot of people do. I have a 46RH behind my 512. the nice thing about it is that it has a lock-up (3000 stall, and .68 final, something a gear vendor can't do) and it is basically hydraulically controlled (unlike the 4L60E) and will handle 700hp. yeah I had to modify the torsion bar frame and dimple the floor but its worth it.

 

[33 IMP]

@dcmason69 , forgive me asking a question. Is this for a 69 coronet model 440 with a small block, or for a 69 coronet with a big block 440 in it? Advice will differ.
Edit: i understood it was a big block, i realize i may be wrong. If it is a big block, there are no mopar overdrives that will fit without some sort of adapter. (but i'm betting you knew that.)

 

[493 Mike]

I have 2 Gear Vendors in my 65 and 66 Belvederes. In both cases I had sheet metal rolled to enlarge the tunnel for clearance. I have had the 66 done for 8-10 years now and it works great. No way do I want a GM tranny in my Mopars!
Mike

 

[dcmason69]

I have fit a 46RE in a 1973 Ebody, with only a few blow of the hammer on the tunnel, and some slight grinding on transmission case.(needed a custom made trans mount with a 700r4 rubber)
But no cutting the tunnel, or Torsion bar X member.
I DO NOT KNOW if it would be the same on a B body.
Also my Challenger had a 5.9 Magnum in it, not a 440, so I realize the trans would have to be build to handle your 440's power level.

I have read about a lot of guys running truck 518's, I think its almost the same as a 46RE.
For me I cant afford a $8,500 transmission so I had to go with a less expensive option.

I also look forward to reading responses to your question.

O/K Thank every one for your input, I will look into the 518 option again.
This car is a 69 Coronet with a 440 BB just to be clear.
I talked to a reputable Mopar tranny guy and I believe he said that he could make a 518 O/D to use my main case.
I will talk to him some more.
I am afraid to change pinion angle too much with GV's

 

[dcmason69]

put a 518 mopar in it . check on google it out there.https://transmissioncenter.net/shop/727-to-518-transmission-swap-information/

Yes thank you I have looked at that artical web site, just not sure about having to cut into my torsion bar channel.
appreciate your input.

 

[dcmason69]

What is the problem with Gear Vendors? It effectively turns your 904 or 727 into a six-speed automatic with dramatically better ratio spreads than a 4L60E, especially with the 4L60E's massive, crappy dump between first and second. Torque multiplication is hugely important in the lower gears, so I wouldn't give it up just for an overdrive gear on top. You get to keep the Chrysler transmission, have more gear ratios available, and I believe it's cheaper than the SST A41. https://www.gearvendors.com/hrdodge3s.html

But, if you are still leaning SST A41, here is an installation article: https://moparconnectionmagazine.com...smissions-a41-perfectfit-overdrive-automatic/

 

[dcmason69]

Thank You for the lead on the article was very informative, I do not want to tear up my crossmember to fit a 518 or use a GV.
This SST kit to me will be more favorable to me I know its a GM but I am not building this car to please all of the Mopar nation I am building it for me. I love this car and I appreciate all the input I got. So I have not bought it yet but am considering it.
Thank You wish4hemi
dcmason69

 

[myk r sanchez]

I wouldn't hook up a 4L60 or 80 to a hamster wheel let alone a big block engine. I've owned my two 4th gen F bodys for decades and they eat 4L60's for lunch. My cars are stock and are never run hard so theres no excuse for these transmissions to break, but just like anything 90's GM they have a glass jaw.

As for anything else, I find it hard to believe that there are options out there that don't involve a BFH. The trans tunnel in these 60's cars is relatively small and it's the over drive components in a modern transmission that take up more room. Good luck with your search...

 

[Ruby67]

I put the SST A41 in my 67 Coronet behind a mild 360.
The kit was well designed, components were good quality, documentation was very good & the install went mostly as expected.
This is my first summer driving it and it's been great for cruising with 3.55 gears.

 

[wish4hemi]

Thank You for the lead on the article was very informative, I do not want to tear up my crossmember to fit a 518 or use a GV.

It sounds like the GV would be a decent fit for the application, but your mind is already solidly made up on a 4L60E. Either way will ultimately end up being just fine since both are made and supported by good companies, but you might not find the 4L60E love you were looking for here.

For clarification, the GV shouldn't require crossmember modification. Also, from the 904/727 GV manual, "Since we did not change the angle of the engine or diff then a one piece should not typically need any angle adjustment because of our overdrive installation."

 

[furyus]

I thought I saw somewhere that the Gear Vendors setup requires a full manual valve body. Any truth to this?

 

[F4R/T]

Did you contact cope or A&A trans as these guys can really help if you ask!