Is th conversion from a TH350 to a 700R4 a simple bolt in conversion or do i have to change things like the driveshaft and speedo cable and shift linkage ect.
You MIGHT need a shorter driveline, and a different yoke. You will also need to add a TV cable to control line pressure, and maybe a different throttle cable bracket to accomodate the trans cable,as well as the hook up on the bottom of the throttle crank.
You can control lockup with the computer, but you may need to add the harness for that if its not there, along with the proper computer chip. alternatively, you could install an external lockup kit.
I would consult a local transmission shop with the driveline and yoke, as you can have them look at what you have already.