th350 vs th400 ???
Thread Starter
Racer
Joined: Jun 2003
Posts: 357
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From: swansea ma
th350 vs th400 ???
My car came with the th350, what is the difference between that and the th400? The car needs a new tranny and a buddy has a th400 in his garage. Is it a bolt up job or are the crosssmembers different, would I need a new drivshaft?
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by Joebio
My car came with the th350, what is the difference between that and the th400? The car needs a new tranny and a buddy has a th400 in his garage. Is it a bolt up job or are the crosssmembers different, would I need a new drivshaft?
The crossmembers are not interchangeable, as the Turbo 400 has a different rear mount. This however, is still a 3-speed transmission. The 700R-4 is the hot setup now.
You get all the benefits and features of the turbo 400 but with the addition of an overdrive.
Last edited by SanDiegoPaul; Jan 13, 2005 at 01:33 PM.
Melting Slicks
Joined: May 2002
Posts: 2,508
Likes: 0
From: Wisconsin
The 200-4R is the better setup than the 700-R4, more of a bolt in affair.
I would just rebuild the TH350. You don't need the extra strength of the TH400, your car will probably be slower with it anyways. The sooner you're on the road, the better.
I would just rebuild the TH350. You don't need the extra strength of the TH400, your car will probably be slower with it anyways. The sooner you're on the road, the better.
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
You can increase the strength of a TH350 significantly by doing a few modifications. The most common failure in a TH350 due to too much power is breaking the sprag clutch. B&M, TCI, among others make heavy duty versions that increase the torque capacity of the trans. I'm running a TH350 in my street/strip drag car behind a Olds 455 making 500+ ft-lbs of torque .... haven't had a failure in over 10 years (knock on wood 
). Just thought I'd mention this as another option for you. 
**However, I should note that I don't run slicks so the shock load is reduced on tranny. My 60' times is 1.6 sec. for FYI. **
). Just thought I'd mention this as another option for you. **However, I should note that I don't run slicks so the shock load is reduced on tranny. My 60' times is 1.6 sec. for FYI. **
Melting Slicks
Joined: Jul 2004
Posts: 2,577
Likes: 2
From: Long Island New York
Originally Posted by Schmucker
The 200-4R is the better setup than the 700-R4, more of a bolt in affair.
I would just rebuild the TH350. You don't need the extra strength of the TH400, your car will probably be slower with it anyways. The sooner you're on the road, the better.
I would just rebuild the TH350. You don't need the extra strength of the TH400, your car will probably be slower with it anyways. The sooner you're on the road, the better.
Instructor
Joined: Apr 2004
Posts: 137
Likes: 0
From: Princeton MN
I just converted my 69 to the 350,had the 400. The drive shaft is the same.Just change the yoke. Also you would need the 4 speed trans plate that mounts to the crossmember.I did it for the weight savings,and the fact that the trans was fully modified for my horsepower and had all roller internals,so it should be a little quicker because it robs less power!
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