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OK so I have what I thought was the original trans to my 72 formula the guy that built my tranny says it was made in 72 as the first numbers are 72 followed by BC which I believe makes it a buick trans? Here is my problem. It has a 9 1/4 inch tail. Everything I read on google says the ones that came with a 9 inch tail were used in the bigger cars and were actually th375s and had a 27 spline count but mine does not say th375 on the bottom of tail and it also has a 32 spline shaft. I searched google for hours and cannot find another trans with 9 inch tail with 32 spline count???? I am just trying to figure out exactly what trans it is and make sure it will work ok with my setup. I don't understand why this is so hard to figure out. I asked everywhere and nobody can give me a good answer though two people I talked to claimed they each had one in their garage. DID THEY EVER MAKE A TH400 WITH A LONG TAIL AND 32 SPLINE COUNT AND IF THEY DID WHAT CARS WERE THEY PUT IN? Two drive shafts also came with the car I measured them from the center of the holes one measured 48 and the other 52. Do either of these sound like the correct length? Thanks in advance! I am at the point in my build where I want to buy a torque converter and driveshaft and would like these questions answered first.
 

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"...DID THEY EVER MAKE A TH400 WITH A LONG TAIL AND 32 SPLINE COUNT AND IF THEY DID WHAT CARS WERE THEY PUT IN?..."

Yes--they came in lots of GM big cars. :yes

All the Bird TH400's had the short tail. Most of the big cars, except the '69-up Grand Prix had a long tail TH400.

I recently discovered that my bracket '74 Ventura had a long tail TH400 in it. That is probably because whoever built the car found a long tail for a lot cheaper price. There were obviously a lot more big cars made than small ones, back when the TH400 came in cars. So, it makes sense that the long tails are more plentiful and cheaper. I took a long tail to my tranny guy for a rebuild, and he swapped out the long tail parts, and replaced 'em with short tail parts. The rest of the parts are the same, in long and short tail models.

Although not technically a Pontiac part, any BOP (Buick, Olds, Pontiac) TH400 should be just as good. I think Caddilac also used 'em. You can even use a Chevy TH400, with a cheap adapter plate. The guts, from like years, are all about the same.

But, the long tail is obviously not original to your car. I'm not up on how to read the codes and ID numbers, on the trans tags. But I do remember looking at some of the tags, back when I raced a lot, and set up several cars. I assume all the trans ID info is available somewhere online. When I get time, I'll see if I can find some good links. :smile22:

Here's a chart with some of the 2-letter codes. All that start with a B are indeed Buick, C = Chevy, & P = Pontiac.

http://www.teufert.net/trans/t-400.htm

Looks like a '72 400 4-barrel Firebird would have had a PG.

Here's a PR-69 tag on a rare TH400 from a '69 428HO GP.
 

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