I want to get overdrive in my 59 chevy daily driver. It has a turbo 350 right now. Has anyone done this swap, and do you know what it involves? Moving crossmembers? shortening driveshaft? etc?
If your current trans is a short shaft 350 turbo, you will need to make a change to the trans crossmember where tailshaft sits..It will need to be set back 2". A simple plate with 4 holes...two to bolt to current holes and the other two rearwards 2" will adapt that to fit the crossmember ya have..... So.. a 2" reduction in driveshaft is also necessary...
I just got done installing a small block overdrive set up in my 60 wagon, and i love it. I think the 700r4 is 2" longer than the 350, so you have to cut and move the crossmember back. Some advice given to me was to cut the crossmember on both sides where the beefy part becomes a tube, now if you can picture this, after you make your cuts, and you now have your three pieces laying flat and upside down, slide the middle piece to what would be to the back of the car and leave just 3/4" between the front of the inside of the tube piece and the back inside of the two outter pieces. at this point that measurement should put your tranny mount back where you need it to be. From here you can tack it all back and do as you wish to box it, weld it, and make it strong enough to hold up to your specifacations. You will also need to shorten your front driveshaft, probably about 5" or so but measuring for this after your crossmember and tranny are fixed back in place. Measure your shaft from the center of the u-joint on the yoke of the tranny, to the center of the u-joint on the yoke of the pinion. This worked for me and i was within 1/8" of where i wanted it. makes things easier if you have a loose yoke to install at your tailshaft and remember to leave some gap so your driveshaft doesn't get into a bind under suspension movement. i looked at where the original was and left that much for the new one, thinking about 1 1/2" or something close to that, yours may be slightly different than mine. I did my swap a little different, I put the small block on the original six cylinder motor mounts ( sounds silly, but when i was measuring i found that sitting the motor here with the 700r4 on would let the tranny bolt right back to the crossmember without any cutting ). There are two sets of holes, upper and lower for the crossmember to mount to and i used the lower. Doing all this let the speedo cable go in with a little rerouting and I got to reuse the forward-back rod from the old shifter, which went right into place on the shift arm of the tranny so i could still use my column shifter to keep it stock looking. All in all I think I shortened the front shaft like 7 1/2" or something and it works like a charm. Keeping the motor forward gives more room for fire wall clearance and moves fan closer to radiator with still plenty of room. Anyway this is my 2cents and it works well.