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Who has used a "Low" gear set in their 727?

Kern Dog

Life is full of turns. Build your car to handle.
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The 904s started being fitted with the low gear sets sometime in the late 70s, right? My understanding was that it was a crutch instead of simply designing an overdrive transmission. The lower 1st and 2nd gear gave the feel of deeper axle gearing so the diff could actually be lowered numerically for the reduced cruising rpms.
I'm not all that happy with my 727 in the Charger. It was rebuilt several years back but shift quality has never been great. I've thought about having it built right using some quality parts including a low gear set instead of floor modifications to accomodate a 518 or some other setup. I ran a Gear Vendors but wasn't all that happy with it.
Using the low gear set, I'd still be able to keep the converter that I have along with everything else, linkage, drive shaft, etc.
Has anyone here used the low gear set for their street car?
 
I have the low gear set in my 727. I have a 4.30 year set and a 30" tire. I race with it. Best of 10.64 @ 127 with a 1.48 60. Not bad for a 4100 pound tank.
 
I run a Lower planetary 1st gear in my trans, and 4:10 rear end gears, Dave at Pro-Trans said its more like a 4:56 in first gear with 4:10 in back, once you shift into 2nd its back to 4:10, does that make sense to anyone LOl personally i love it !
 
Is there a quick reference for the factory gear sets in the 727?

Were they all the same?
 
for street driving i think a low gear set with a 3.23 or 2.94 rear and a fat torque engine would be great. in fact i'd like to do it;.... until i look at the price tag for the gear set.
 
I have the low gear set in my 727. I have a 4.30 year set and a 30" tire. I race with it. Best of 10.64 @ 127 with a 1.48 60. Not bad for a 4100 pound tank.
I don't want to hijack the thread but was wondering if you could PM me the details of your build? I am trying to build a 10.50 car and am looking for some guidance. I also am running a 4100 pound beast. Thanks.
 
I don't want to hijack the thread but was wondering if you could PM me the details of your build? I am trying to build a 10.50 car and am looking for some guidance. I also am running a 4100 pound beast. Thanks.
It can be done. It like anything takes lots of $ to make it happen. Search my old posts and you will find most what you need. If there is anything specific Feel free to shoot me a PM.
 
for street driving i think a low gear set with a 3.23 or 2.94 rear and a fat torque engine would be great. in fact i'd like to do it;.... until i look at the price tag for the gear set.

2.94 is VERY common on 66/67 cars.

3.23 is by my count third most common after the afore mentioned 2.94 and later 2.76.

Should be relatively easy to find those and fairly cheap.

The real cost is the SG unit.
 
SMR Trans has a 2.77 front planetary low gear set

so does A&A {Coan too IIRC}
I have used A & A in my altered years ago,
they use to have 2.28:1 & 2.45:1 tried both

but it had 33" x 15" slicks 4.56:1 gears
Blown Alky hemi/or wedge spinning 7500 rpms
only weight 1800#'s too,
hard to do an apples to oranges comparison to a 4000# street car,
I mainly did it so it would live,
better materials & heat treatments {we had stuff cryogenic treated back then}

I also sat straddling the trans in the car, sitting/laying over the rear axle,
I wanted to be safe as possible, my legs & jewels were on the line...LOL

never done a low planetary gear set in a street car,
I never saw the need...
Different animals, different types of builds...

There are straight cut planetary's too,
not sure that'd be the way to go on the street either...

I'd call either of them listed & talk to the experts,
keep us posted what they said...

I think if I understand you correctly, your accessing doing it
to run a higher gear {lower numerically} out back
& still have some grunt down low, like if you had a lower rear gear...

the final 1:1 ratio will effect your converter choice for sure,
more than the low gear planetary set would/should, on the street anyway...

carry on
 
Or you could call Rick at A&A transmission, Great customer service....
 
The 904s started being fitted with the low gear sets sometime in the late 70s, right? My understanding was that it was a crutch instead of simply designing an overdrive transmission. The lower 1st and 2nd gear gave the feel of deeper axle gearing so the diff could actually be lowered numerically for the reduced cruising rpms.
I'm not all that happy with my 727 in the Charger. It was rebuilt several years back but shift quality has never been great. I've thought about having it built right using some quality parts including a low gear set instead of floor modifications to accomodate a 518 or some other setup. I ran a Gear Vendors but wasn't all that happy with it.
Using the low gear set, I'd still be able to keep the converter that I have along with everything else, linkage, drive shaft, etc.
Has anyone here used the low gear set for their street car?
It's not really a crutch....it works well to get a heavy car rolling from a stand still. It's kinda like a granny low in the old 1 ton pickups but not nearly as low. If you are running a cruiser rear gear, the low gear setup works very well. What was the problem with the Gear Vendor unit? Been thinking about running one instead of going with the T-56.....


I don't want to hijack the thread but was wondering if you could PM me the details of your build? I am trying to build a 10.50 car and am looking for some guidance. I also am running a 4100 pound beast. Thanks.
You can also go to the 'post your 10 second combos' in the Racers Hangout for quite a bit of info. There's like 25 pages worth including what I ran in the early 80's. Today, it's not hard at all to run 10's....at least compared to 30+ years ago.
 
It's not really a crutch....it works well to get a heavy car rolling from a stand still. It's kinda like a granny low in the old 1 ton pickups but not nearly as low. If you are running a cruiser rear gear, the low gear setup works very well.


Cranky is right. Getting a heavy car out quick is key to a good 60 foot which equates to a better ET.

I love my 2.74 low gar set from A & A Transmission

65 plymouth hemi wheelstand 9.19.15.jpg 63 plymouth savoy4  10.15.15.jpg
 
2.94 is VERY common on 66/67 cars.

3.23 is by my count third most common after the afore mentioned 2.94 and later 2.76.

Should be relatively easy to find those and fairly cheap.

The real cost is the SG unit.
I have several 3rd members here. I've never priced that low gear set though. If it is too spendy, a Gm 2004R might be a better way to go.
 
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