If this is a near stock 350, used as a street truck only, you will be fine with a 700R4...but as noted, you will need to set up a TV cable mechanism and get it set right.
Sure you can go the whole hog and install a 6L , but the costs are up there...stand alone controllers are around $800, then the trans itself...say $2000, etc...
200R4 can go in where a T350 comes out with only some small changes...but again, you will need to setup a TV cable system...
Just do your research, count your pennies and keep us up to date...
