700R4 Conversion

[ms4972]

How difficult is it o make the changeover to the OD transmission?  Will my factory tranny x-member work?  Will I need a new driveline?

[Captkaos]

You need to move the crossmember back and redrill mounting holes for anything Pre 1982, in general.  You will also need to modify the location of the mount on the frame by moving it back to get all the gears.

[Dragon]

Generally you will need to shorten your driveshaft as well, unless you got the correct length one from the donor truck...

[Captkaos]

forgot to list that, thanks Dragon.

[86swb]

When you go from the 350 and if you now have a 3:08 rear in it you would also be best to change to a 3:73 rear end. I had to do this when I changed to a 700R4 in my truck. You even get better gas mileage with the 3:73. The gears in the 700R4 are different than in the 350. I did not have to shorten my driveshaft. My 350 had the shorter shaft already in it. I also changed the gear indecator over to an overdrive indecator. You can find these on ebay.   

[Leevon]

Here are a couple of things to think about also; new dipstick if one doesn't come with the trans, new TV cable, and lock-up stuff.  I put together the lock up with free junk yard parts (vacuum switch and cruise/brake cancel switch).  I swapped from a TH400 and had to lengthen my driveshaft.