man trans fitment question on 72 gmc

[60ratrod]

ok so i am gonna be doing a cab swap on my 72 and i found a cab that was a 3 on the tree. my question is what manual trannies will fit that manual 3 on the tree cab and go in place of my short tail th350? i haven't had a manual in a while and have been wanting to get one for some time. mind you that this tranny will eventually be behind an 88 tpi 350, so one that uses the 3 on the tree/th350 drive shaft, and mine is the 2 piece drive line

[raycow]

If you want to use the TH350 driveshaft and stock column shift linkage you will need a 68-up Saginaw truck 3 speed and a 68-72 truck bellhousing. Another possible combination is a 66-up Saginaw car 3 speed and a 63-67 truck bellhousing. The only difference is the diameter of the front bearing retainer on the transmission and the center hole in the bellhousing.

Ray

[60ratrod]

is there other trannies that have the same length as a th350 that's a 4 or 5 speed?

[raycow]

Originally Posted by 60ratrod

is there other trannies that have the same length as a th350 that's a 4 or 5 speed?

Most car 4 speeds like a Saginaw, Muncie or T-10 are the same length as the short TH350. Some of those will have a 32 spline output shaft, so you would have to change the yoke. You won't be able to use a truck 4 speed without replacing the driveshaft AND going to a high hump.

For a 5 speed, look at a NV3500. It has the right length and output spline, but it needs hydraulic clutch linkage. I put a T-5 in my truck (it originally had a 4 speed), so I had to replace the driveshaft anyway. The T-5 has the same output spline as a TH350, but I think it is somewhat longer. I found a salvage yard shaft that was a good fit. No clue what it came out of.

Ray