I just did this swap to my 77 swb, , kept the stock 350, but put in a 700r4 and the 208. You will most likely have to get new drivelines, I did. The old ones just wont work, besides your gonna want all new stuff anyway. I also went to the local pik n pull and got as much as I could for the swap out of a k5-k10 that had what I needed, cross member, 4wd shifter, the gear indicater off the dash cluster and other things that were needed. you can use your t350 shift linkage, it will adjust to the 700r4. you will have to move the 700/208 cross member back I believe, and drill only two new holes to bolt it up. If you go 700r4, make sure you get your tv cable adjusted correctly.