trans length question

[bbcmonte]

I am going to box my frame in on my 1970 Monte Carlo and I believe I have to go with a different type of trans cross member. I plan to go with a t-56. My question is is a th400 the same length as the t-56? I want to measure for the right placement of the t-56.

[astroracer]

What tail shaft is on your th400? Main body length is about 25" on the trans and overall length is decided on tailshaft length of 4", 9" or 13"... A T56 is about 26 1/2" long.
The mount on a 400 is almost 28" from the block face. A T56 is about 21" from the block face.

[camrat68]

http://chevellestuff.net/tech/automatic_trans_dimensions.htm

-Jim

[bbcmonte]

Thanks,

[Toddoky]

The mount location of a TH400 with the 4" extension housing is 1/8" to 3/16" further back than the mount on a 4th-gen F-body T56 (most T56 crossmembers have slotted center holes so the disparity is not usually noticed). The mounting pad is also machined 1-5/16" closer to the trans output shaft centerline on a TH400, so you'll need to create a spacer of that height to be able install the TH400 using a T56 crossmember. The 2004R shares the same install dimensions as the TH400, so the same rules apply for installing one of those.

[bbcmonte]

Thanks, I plan to use a t56

[chpr1972]

For future reference, The 200R4 is not the same length or rear mount the same as a 400. The 200R4 is the same length, spline count as a muncie 4 speed and a turbo 350, Basicly a 200r4 is a bolt in in place of a 350 using drive shaft, crossmember and rear mount. The only thing that needs modified/replaced is the shifter. Art Carr claims he can build a 200r4 to 1000 hp. Other than ease of changeover you do not have the linchage adjustment problems that the 700r4 has.