definetly do the sas. i assisted on ToThe Floors truck doing the body swap, and did it to my 83 when i swapped frames. sas is a cake walk, if you have an idea of what your doing.

next you asked about swapping engines, yes the harness unplugs, but the question is are they both carb and carb, or efi and efi. if not then its a whole new game

alright i have never done anything like it, my dads truck is stock and he dosen't wheel i kinda got into it all by myself thanks to tv. he dose know alot about the truck and is a valuble resource. and its a carbed 84 and efi 86, 86 motor 86 body is what i'm gunna use. thanks for all the replies guys.