700r4 to TH400 two questions

[Slammed84]

Originally Posted by beamn7

When I smoked my original 700 I tossed in a 400. Frame is pre-drilled already. Just moved crossmember back and lined it up. I used a truck trans which has the short tail shaft. Mine is two piece drive shaft so I just changed the front half with one that had a 400 and installed it on the original rear half. Worked great. Don't forget to install a vac line for the modulator and the kick down switch that mounts under the dash to I the accelerator pedal bracket. Bracket is already stamped to accept the switch. Just install and wire.
I've since built and installed a 700 to withstand what's under the hood and then some as I like the overdrive but you can't beat a 400.

I forgot about the driveshaft issue. I robbed the one from the truck I got my 400 from along with the crossmember. I just had a local driveshaft shop cut the longbed shaft down to shortbed length. I had to drill new holes to mount the crossmember, I believe just the front holes lined up.

Another option for the kickdown switch is the B&M one that mounts on the throttle linkage. Pretty slick