I just changed my 350 tranny for a 700R4 three weeks ago. All I can say is do it, 4th gear in 700R4 is usually a .7 versus your 3rd gear in a 350 tranny that is 1. I am enjoying the gas milage.
My suggestions:
Go to
www.700r4.com and put in your tire size and back end ratio to get the drive and driven gear numbers for the speedo, changing these is not fun after you install the 700R4. Have builder install these for you.
Also if you have a 6" tail on the current tranny you will have to shorten the driveshaft about 3".
You will have to move the transmission crossmember or get an after market one that is made for this swap (about $55 on EBAY)
I used the TCI tourque convertor lockup through the brake switch, wiring inside the pan and vacuum to the carb. Do this wiring in pan before installing into truck also.
I had to get a longer speedo cable, mine was the original and a little short.
And connect and install the TV cable correctly, if you do not you will have to but another transmission.
Good luck
