87 TPI 350 in a 94 GMC Vandura with a 350 TBI

I have a 94 GMC vandura with a 350 TBI, 4L60E. I have a complete down to the sensors 350 TPI out of an 87 Firebird. I want to put the engine, Complete with the tpi, into my van. My question is, what will I need to change to run the engine and the transmission. I have heard that all I would need to do is add my injector wires and run it, but I have also read that I will need to piggyback the computers, or I can run my computer, but it will need a completely different tune. I have been on the chevy talk forum, Thirdgen.org, and others reading ans searching. Can anyone give me a straight answer, lol? FYI, I am planning on eventually putting a 383 or a 400 in the van at a future date. Thanks everyone, William

The 94 computer can be converted to Multipoint Fuel Injection (MPFI), see attached. Been there done that, do some homework it works great!. dave w