Trans. & crossmember ??????

[dsdude]

Hi I have a 1971 GMC and I am looking at putting a 700R4 instead of the farmers 4 speed in. The truck is stripped down to the frame. The question is will the crossmember work or will i need to made a trip to the bone yard. And if it will not work what will? Thanks James

[sweet70beast]

2wd or 4x4? If 2wd I don't know if the manuel crossmember can be made to work because it mounts under the bellhousing, if it won't get one from an automatic truck. A few years ago I put in a 700r4 and used the original crossmember in my old 72 GMC it had a th400. Idon't remember if I had to drill new hole in the crossmember for the trans mount but a th350 mount will bolt right to the 700 and the holes where already in the frame in the right spot farther back because the 700 is longer then the 400 and 350.

[mrein3]

4x4 you use the same crossmember but you have to change the output shaft in the tranny. And you need to move your engine forward close to two inches or move the t-case/tranny back that far and cut the rear and lengthen the front driveshafts.

[odog]

I did the opposite, I put a sm42o in where there was a 700R4 in a 4x4. I had to move the crossmember forward so the Tcase would mount right, but I used the same crossmemeber.

[dsdude]

sorry it is a 2 wheel drive

[Ole Blue 68]

Originally Posted by dsdude

sorry it is a 2 wheel drive

Find a 2WD 67-72 with an auto trans and that's the crossmember you'll need. It will pretty much bolt in place of your manual crossmember.

[Jerblazer72]

Originally Posted by mrein3

4x4 you use the same crossmember but you have to change the output shaft in the tranny. And you need to move your engine forward close to two inches or move the t-case/tranny back that far and cut the rear and lengthen the front driveshafts.

Whats easier? Move the engine forward or drivetrain back? How do you do each option??