Need this info before i commit to buying driveshaft..Do the 400 TH,the 350 TH share the same tail spline count.? Sent from my SM-T560NU using The H.A.M.B. mobile app
In a word NO. HOWEVER, there IS a TH400 that has a TH-350 output shaft SPLINE; they are somewhat "rare", and were called a TH-375. Even with the "true" TH-400's, there are some minor differences, and the output shaft/extension housing/rear bushing can be one of two sizes. And then there's the bolt-on (3/4 ton and bigger trucks and Corvette's (due to the Vettes independent suspension/swing arm rear ends after 62) VS slip yokes and variances in the slip yokes of the TH-400. Get your transmission, and let the drive-line shop figure out what you need when they build your shaft. I am Butch/56sedandelivery.
I've never seen a short 375, interesting.. The one's I've seen were early 70s full size car. If the plan is to install one transmission now, and another one later, it's not so easy.
Back in the day, the front yoke I often used when switching from a PG, 350, Muncie etc to a 400 was an Oldsmobile one that used Spicer joints, then used a step-down U-joint to mate up as needed. Can't remember the exact year Olds, but it would have to be mid 60's -early 70's. FWIW.
TH350 has 27 splines and TH400 has 32 splines. Correct. Here's a quick snip I found when I was researching my TH475 transmission. The TH375 is in the bottom right corner. Albert
The Jalopy Journal
