The Stovebolt Site Forums The Shop Area Driveline 700R4 in my '55 3100 - trying to maintain original appearance.

Hi guys. I’m looking at upgrading the transmission in my ’55.2 from the old 3-speed with granny gear to an automatic overdrive (700R4). I stopped by a local shop and the guy I talked to said he could connect the 700R4 to the original 3-on-the-tree shifter with some work so I could keep the original steering column. I have the original 235 stove-bolt installed and I’m 99% sure I have the stock original 3.9:1 gears in the rear end. I’m trying to keep the look as original as possible and yet save some cash at the pump (currently getting between 12 and 15 mpg at ~60 mph highway). Some questions: 1) Has anyone dropped a 700R4 into their 3100? Were transmission tunnel modifications needed? I’m trying to avoid cutting metal at all cost. 2) Has anyone been able to keep the stomp-to-start pedal functionality with a 700R4 setup? 3) Has anyone bothered connecting the 3-on-the-tree shift linkage to an automatic transmission (of any type)? How is that working for you? 4) Do you have any recommendations that would work better in this scenario? I do not want to cut any holes in the floor. I like it when my lady sits right next to me. :cool:

Hy Chenzo, I'll start by saying I have not done this swap. In order to mount the 700R4 to the 235 you'll have to purchase an adapter kit, which I believe includes a new flywheel and starter. I don't think you'll be able to keep the stomp starter. The adapter will move the transmission away from the engine, and closer to the cab by at least one inch, so I think metal work may be required. The 700R4 has a very intricate throttle pressure linkage/cable adjustment and setup procedure, and if this is not setup and functioning correctly, you'll burn up the transmission in short order. I'm not trying to talk you out of the swap, I'm just trying to make you aware of some of the problems with this swap. If you search around on transmission forums you'll find more info on the throttle linkage setup, hope that helps.