Are you planning on using the on board computer? What kind of fuel injection do you have now and what kind are you getting into? Then get the puter from the donor car too. No way to accomplish this with a 6cyl computer. After that change the motor and find both real accurate wiring diagrams. If you have similar fuel delivery systems, you may make it work. Perhaps throttle body on both the donor and the original would be the easiest swap.
Sensors have to match up pretty well. In my books this is the easiest swap.
TPI wont be possible without wiring harness from donor car. I'd get the wiring harness for the computer from the donor for it just to be sure. Seems like this is a swap for experienced electronics guys. I can do it, but it would be a challenge to most of us. TPI has its advantages when perfect, but its completely unforgiving.
The easiest route is to do away with the puter to begin with, but you'd have to go to a carb to do it easily and thats not as economical, but more fun if you step up the cam before dropping the motor in.
Btw I read this as if you were going to a v8 the first time I looked at the question. Almost all applies but if the engines are both v6's and fuel delivery is similar, you may pull this off with a couple of nites at the wiring diagrams and trading the puter completely.
