Quote Originally Posted by tango
Ok on your TH350 Long tail it's 30 11/16" in overall Length . And the Front edge to the mount is 20 3/8" . Now on a TH400 short shaft . It's 28 3/8 overall Length . And the Front edge to the mount is 26 15/16" . This means you would need to move your crossmember back . That should not be a problem . And many Chevy trucks came with TH400s and the frames are drilled for this . Now the biggest thing you would need is a Longer driveshaft with a TH400 yoke with the bigger tail shaft splines . Also the Filler tube is different then the TH350 . One other trans that you could use is the . 700R4 That one is 30 3/4 overall Length and the front edge to the mount is 22 1/2" . Also it uses the same drive shaft yoke splines as the TH350 . And the drive shaft length will fit from your TH350 to the 700R4 . I do not think this one is good for you because they are to high priced . I do think with you being on a budget . It would be best to go to a Junk yard and find a clean Long Tail TH350 . I had a 1974 GMC Pick up that burned out the TH350 . I bought one for $100 bucks at the Junk Yard . Then I changed out the Filter and front + rear seals . Picked up some new O-rings for the filler tube and kick down cable . Filled it up with Ford Type F fluid . The ford fluid will make the plates grab more . Many Trans guy here run it in there builds . And your good to go . Now I would not beat on this trans . It will work fine (To and From ) . Later when you have the Fun-es . Do the TH400 Swap .
can't always rely on a junk yard though i went through 6 of them before getting a good one well it wasn't good but it worked it didn't have second gear but all the others didn't work at all or slipped plus spending tons of money on tranny fluid but for $100.00 you can get a th350 rebuild kit from Napa rebuilding them is fairly easy just keep the parts in order as they come out an have patience with the lip seals during reassembley. if you cut a lip seal it'll slip. but you will also need tools to do it, snap ring pliers to open an take out C-clips an a spring compressor for the clutch packs I get all my TH350 stuff from older guys at napa that know what you need an what your talkin about. to many younger guys that are like umm uh no we don't have that. but the master rebuild kit you want has all the seals an gaskets with the clutch discs an metal discs for around $80 - $100 for a th350 1968 - 1980