Correcting a Hodge-podge mystery 727

[jeepthrills01]

So a trans I acquired years ago is being pressed into service.

It was allegedly rebuilt..(I agree) and with Hemi parts (mostly disagree).
So I found 4 new waffle cut clutches per drum..ok..not hemi..but not 3 either.
4 pinion planets, 9 springs in the front drum, and a sad little 3.2 lever.

The 3.2 is getting swapped...no question to a 3.8 or 4.2..(agree?)
I'm thinking i need to add for 10 or 12 return springs ....would it be more helpful/ notable than 9 with a transgo and 3.8 or 4.2? Opinions?

Reminder...this is going behind a warmed up 383 (9.7 measured, voodoo 702 hyd, Eddy heads, RPM manifold, AVS2 800, headers, 2.5 free flow exhaust with 3.73 gears (don't hate...got a deal! Lol) and 2500 Hughes converter in a full street trim 69 Coronet.

 

[R413]

Sounds like a fun car, not overdone for the street.

Use the 3.2 or 3.8 lever. Not the 4.2
# of Springs? well lots of things come into play.

 

[jeepthrills01]

Between Tom's book and the FSM...I'm not finding a good answer as to determine # of springs.
I do see 1969 trans (hp varient) used 10 springs, 12 in the hemi..but the 71 and
on...only 9. This is a 62-70 unit.

 

[Dave6T4]

A 3.8 or 4.2 lever would be a nice upgrade. My side hustle was rebuilding 727's for friends,etc. Likely 150 of them over last 40 years. I usually tried to build them with 9 or 10 springs, depending what style piston was in the trans. I recently had the opportunity to rebuild a 727 that decoded to be from a 1970 383HP, that had never been apart before. It had 3 pinion planet in the rear, and 4 pinion in the front. 4 clutches front and rear, with 3.8 lever. It had 6 springs in the front drum. My 1969 shop manual confirmed this combination of parts for a 383HP. I usually left the spring off the accumulator piston, but did not put blocker rod under it. You might want to pick up a higher upshift speed governor weight set from A&A transmission. I used to have a machinist friend modify the stock ones for me.

 

[dvw]

To be honest in a street application it doesn't really matter. Some cars running traction limited stuff run 2.7 or 2.9 to help with wheelspin on the 1-2 shift. It all depends on the valve body calibration. Plenty of ways to dial in overlap on the 2-3. 4 friction plates are a good idea for sure. The accumulator spring really only cushions when you the trans is put into gear. Never seen a 3 pin planet fail. Even in race apllications. In fact unless the front splines strip only ever seen 2 planetaries fail. Both times it was a needle bearing failure and they were 4 pin. Been running 3 pin in my racecar for 12 years over 1050 passes (9.0@150@3350#) Though the front factory aluminum carrier has been upgraded to steel after stripping the splines. Open up a 904 gutted 727 Pro Trans and you'll find stock servo pistons as well.
Doug

 

[Voetom]

I vote 9 or 10 springs with the 3.8:1 lever and stock or slightly increased pressure regulator spring.,

 

[451Mopar]

What year, pump, stator support/drum, input shaft and spline count?
I usually put a TF-2 shift kit in and use 10-springs.
E-Bay usually has some good deals on rebuild kits, some with stock clutches, and some with performance clutches, bands, bushings and such.