murraybs

My TH400 just gasped its last breath (which was something along the lines of "I hate you."), so I'm thinking I should probably just stuff an overdrive in there while I have the chance. A friend of mine has one sitting around in his garage and offered to help me stuff it in if I bought the trans off of him for 2 cases of CF currency (). So, the only real question I have is what length I should have the d-shaft cut to.

Any input is appreciated. TIA.

jdmick

I put one in my 75 a couple of years ago and looking back at my posting then it looks like I had 2 3/4" cut off. I don't know what the ending length was or if your 400 and 700r4 tailshafts are the same as mine so check it out first.

c69vete

First make sure that the 700r4 is 87 or later. Most performance rebuilders will not touch anything older than that. Too many problems. Second, you will need to find a tail shaft from a 350 turbo tranny to go into the 700r4. The 400 will not work.
You will need to cut the drive shaft 3 in.
You will need to swap the crossmember or buy a modified mount to bolt in the 700r4.
You will need to move the parking brake roller to clear the front universal joint.
You will need the lock up converter and the wiring to make it work.
Do a search here for more detailed information.

bobs77vet

you measure it after the trans is in place....remember to take the yoke with you so they can balance it.....i think mine was cut to like 29 1/2 ", it was several years ago and i could be wrong....it is a tight fit so measure carefully. and yes i think the 700r4 is a great upgrade