I am in the process of turbo charging my car while doing a 99 into 97 swap.
I bought 99 Squaretop intake manifold. I was thinking that I could just use the 99 throttle body with 99 Squaretop. But now that I am actually in to this swap, I realize the 97 TPS connector plug is 4 pins and the 99 TPS is 3 pins.

I don't think the 97 throttle body will fit the 99 squaretop IM. So what wiring changes do I need in order to use the 99 throttle body with 99 TPS and connect it to my 97 harness?
I will be using MS3X ecu with stock wiring harness.

 

The 4 wire TPS has a wire that basically tells the stock ECU to put it into open-loop fueling at 100% throttle. It shouldn't really matter if you're using variable TPS and a MS3.

 

The 4th wire (not actually one of the end wires IIRC, but one of the two in the center) is either an open-throttle or closed-throttle switch. The other three are your standard 5v/gnd/signal wires. Hook the appropriate wires from the '99 TPS to your '97 harness and you're done. You'll also need to swap the IAC pigtail to use the '99 IAC (desirable as it has internal routing).

 

What I did (94 car, 01 TPS)

Not sure if the colours match across NA years, if not consult a wiring diagram