C4 Tail Housing for Powerglide?
Thread Starter
Instructor
Joined: Dec 2007
Posts: 184
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From: Hilliard OH
C4 Tail Housing for Powerglide?
I'm looking to install a Powerglide in my early C4 in place of the original 700R4. One obvious problem is figuring out a way to attach the C-Beam to the tail housing of the transmission. I'm pretty sure I could find a way to fabricate some kind of bracket system, but would rather not reinvent the wheel here.
Is there somebody who offers a retrofit tail housing for the Powerglide that bolts up to the C-Beam?
Or as an alternate idea, has anybody already designed a bracket for the powerglide, like those I've seen for running a T56 in a C4?
This is for an AutoX car which doesn't need more than 2 gears. Weight savings is the big goal here.
Thanks,
BeerMan
Is there somebody who offers a retrofit tail housing for the Powerglide that bolts up to the C-Beam?
Or as an alternate idea, has anybody already designed a bracket for the powerglide, like those I've seen for running a T56 in a C4?
This is for an AutoX car which doesn't need more than 2 gears. Weight savings is the big goal here.
Thanks,
BeerMan
Thread Starter
Instructor
Joined: Dec 2007
Posts: 184
Likes: 4
From: Hilliard OH
Fab a crossmember, rather than a bracket onto the tail housing?? Do you then have to fab a crossmember to hold the nose of the differential?
Do you know anybody who has done this, so that I can bug them for some pictures of how it was done?
Do you know anybody who has done this, so that I can bug them for some pictures of how it was done?
Team Owner
Joined: Sep 2003
Posts: 25,394
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How do you intend to offset the ratios for the PG, best I recall aluminum were done in only 1.76 an 1.82 1st gear maybe. ATI I believe offered a couple that did high 1.90's and low 2.10's but they certainly weren't inexpensive.
What axle ratio were you intending to use?
I would think the PG choice maybe not a good one for "MOST" but who knows.
What axle ratio were you intending to use?
I would think the PG choice maybe not a good one for "MOST" but who knows.
Thread Starter
Instructor
Joined: Dec 2007
Posts: 184
Likes: 4
From: Hilliard OH
How do you intend to offset the ratios for the PG, best I recall aluminum were done in only 1.76 an 1.82 1st gear maybe. ATI I believe offered a couple that did high 1.90's and low 2.10's but they certainly weren't inexpensive.
What axle ratio were you intending to use?
I would think the PG choice maybe not a good one for "MOST" but who knows.
What axle ratio were you intending to use?
I would think the PG choice maybe not a good one for "MOST" but who knows.
The 1.76 1st gear in the PG is actually steeper than I want. It will put me at 75mph with a 7,200rpm redline, so I will almost surely spend time in 2nd. I've actually looked at the 1.68 gears that ATI offers, but they are WAY out of my price range.
I agree that this is a crazy set up for most, but it should work well for me.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
YES. I would think that it would be easier, cheaper, and less weight to fab a C-beam adaptor for the PG tail than to start fabbing up x-members. There are a lot of advantages to the C-beam design, so I would try to make that work, first.
Le Mans Master
Joined: Feb 2005
Posts: 6,485
Likes: 566
From: Clearwater Florida
..... I haven't checked a powerglide yet but the TH350 tailhousing has the same 4-bolt pattern as the 700R4 and with the proper spacing , it will bolt right up to a D36 C-Beam ......
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
I have a friend who has a turbo 350 and it has a spacer sandwiched in between the transmission and the 700r4 tailshaft.
BTW assuming this is a street car, how do you plan to hook up the speedometer? Even if its not, don't you have to have a speed signal for the LS motor's computer to see? Of course, I could be wrong on needing it for the LS.
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Safety Car
Joined: Apr 2005
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From: Dale City VA
The probelm is going to be overall length.
Powerglides are 6" output shafts. Overall they are alot shorter than a 700R4 or TH400 (which are almost the same).
With TH350's there are 4 different output shaft lengths the 3.75" used in 4X4's, 6" common short shaft , 9" used in Vans and 12" common long shaft used in trucks.
To make a TH350 "bolt up" in a C4 Corvette you have to have a TH350 with the 9" output shaft... then use a spacer block between the case and the C4 specific 700R4 tail shaft housing will bolt on and the tranny will be the right length overall (same as 700R4 and TH400).
Because Powerglide output shafts are not long enough and you can't use a spacer and 700R4 tail shaft housing you'll have to build a C Beam adpater of some sort.
This thread has a few pics of C Beam adapters people have built for a TH400.
https://www.corvetteforum.com/forums...350-turbo.html
Will
Powerglides are 6" output shafts. Overall they are alot shorter than a 700R4 or TH400 (which are almost the same).
With TH350's there are 4 different output shaft lengths the 3.75" used in 4X4's, 6" common short shaft , 9" used in Vans and 12" common long shaft used in trucks.
To make a TH350 "bolt up" in a C4 Corvette you have to have a TH350 with the 9" output shaft... then use a spacer block between the case and the C4 specific 700R4 tail shaft housing will bolt on and the tranny will be the right length overall (same as 700R4 and TH400).
Because Powerglide output shafts are not long enough and you can't use a spacer and 700R4 tail shaft housing you'll have to build a C Beam adpater of some sort.
This thread has a few pics of C Beam adapters people have built for a TH400.
https://www.corvetteforum.com/forums...350-turbo.html
Will
Pro
Joined: Apr 2004
Posts: 621
Likes: 37
From: Texas
Th350
TH350 with the 2" spacer and a 9" tail shaft is a nice clean "easy" install. I have a th350 and a rear exit Hurst quaterstick in the console and absolutely love the setup.
I don't know how it is done but I have a few dirt track friends here at work. They have their th350's converted to two speed by a trans guy here in town. Maybe this would be an option for you.
just a thought
I don't know how it is done but I have a few dirt track friends here at work. They have their th350's converted to two speed by a trans guy here in town. Maybe this would be an option for you.
just a thought