TH-350/700r4 swap

[colt45-2007]

I got a buddy of mine that just bought an 83 custom deluxe 2wd 305/TH350... He found a 350/700r4 for cheap out of an 88 c1500 like mine and he's wondering what all he needs to do to make this work, the motor swap will be relatively simple I know, hes gunna take the intake and quadrajet off the 305 and slap it on the 350 and etc but he was askin me what all he needs to make the 350 to 700r4 tranny swap.... Now I have an 88 so I may be wrong on these older trucks but I told him he would need a shorter driveshaft, maybe have to move the tranny mounts and possibly a different crossmember, if this is true what would be the best truck/car to get a driveshaft and crossmember from? I also told him I wasnt sure how the column shift would work going from a 3speed to 4speed.....

Any Info And Past Experiences "Good Or Bad" lol Would Be Great, Thanks