727 tranny build

[sam z]

I have an offer from a close friend and transmission specialist to rebuild my tranny
for next to nothing. Doing it because he's a nice guy and a long time associate. I'm
basically buying parts, not much more.

This is a big opportunity I think to start getting this car "right." Car now has '72 440
with lower compression, 484 cam, beefed up 72 casting heads (hemi springs, etc).
Car has 83/4 3.91 rear, and 4779 mech secondary holley. The 727 unit in the car now is
essentially an OEM piece to fit behind a 383.

From all observations and reading, I should begin running a higher stall converter due
to the 3.91 gears and mech secondary carb. My understanding of trannys is limited
(I'm sure many of you already figured that out), but my builder mentioned a variety of
things that should also be done, such as some valve body work, I believe he mentioned
something about clutch replacement, etc.

Chime in with any advice or point me in another direction. I trust this guy, but I also
appreciate advice on this forum.
-Sam

 

[droptop]

I would recommend the part throttle kick down from a '71 or newer tranny. Also in all /6 tranny's.

 

[Jim S.]

When I do rebuild mine, I think a "low band apply" valve body that CRT offers sounds like a good idea. It is explained in the middle of this thread by John Cope of CRT...

http://moparforums.com/forums/f82/gday- ... 27-a-9637/

 

[Big John]

When I do rebuild mine, I think a "low band apply" valve body that CRT offers sounds like a good idea. It is explained in the middle of this thread by John Cope of CRT...

http://moparforums.com/forums/f82/gday- ... 27-a-9637/

Keep in mind, that's a manual valve body. No automatic shifting.

 

[george68hemirr]

When I do rebuild mine, I think a "low band apply" valve body that CRT offers sounds like a good idea. It is explained in the middle of this thread by John Cope of CRT...

http://moparforums.com/forums/f82/gday- ... 27-a-9637/

JOHN COPE built the 727 in my car.....the guy is awesome.....yes no automatic features....shift like a stick without the clutch

 

[SomeCarGuy]

Depending on the year of the trans, you could benefit from putting in a PTKD. The early trans will need a PTKD from a 6 cyl trans. A & A sells a repop.

A 4.2 lever would be a good move. A 5.0 isn't. A cheap upgrade. A & A sells them.

A deep pan would be something I would absolutely do. One of the few good parts TCI makes is their deep pan. At least the last one I bought years ago was.

Now is a great time to add a new upshift governor. You can get one to suit your ideal RPM like 5600 or 6000 or ??? Pretty sure A & A is the hookup again for that.

I once added a roller output shaft bearing. Not sure you would see any gain from that and IIRC it requires some consideration for the oiling.

CRT is an excellent choice for parts and advice as well.

 

[SomeCarGuy]

Oh and be double damn sure that the KD is set properly if you don't go to a manual VB.

After years of messign with them, I found that all the way forward at idle did the best for me. All the way back at WOT made for some funky part throttle shifts.

Or you could just stick in an 833 or new Passion bolt in 5 speed.

 

[SomeCarGuy]

I came back and looked at what I first posted. I had typed out all that and more, then something happened, poof it was gone. So I had to type all that again.

I forgot to include a bolt in sprag. I went with those pretty much every time. They tend to be high quality and bite into the case real good, as well as having the bolts for extra security.

 

[sam z]

Thanks guys.

Is my thought process correct on the stall converter considering my differential gears and mech secondary carb?

 

[moparchris]

Thanks guys.

Is my thought process correct on the stall converter considering my differential gears and mech secondary carb?

Not really. The double pumper 750 holley will contribute to you feeling the need for more stall the 3.91s will mask the need for more stall. What makes you want a looser converter is the low compression and ancient .484 grind cam. So a good 10 inch converter will make a world of difference in this situation. The problem with the .484 hemi grind is that the power band is narrow so it will need a fair amount of stall and will make power in a short rpm span but it will feel very strong. I would say that a stall speed in the 3000 range will get you there.

 

[sam z]

Beautiful...thanks Chris.