What all do I need to swap 90 GTU motor into my new $200 project 86 se. I have the wiring harness and the ECU. I have a gtu parts car the motor runs fine.

 

Well that is an S5(89-91) into an S4 body (86-88). You need the engine, with all S5 parts to make it into a long block, and S5 ECU. You might need more things, but those are the essentials.

 

I about to do the same swap, the only difficult part is the wireing harness where it plugs into the ECU. The s4 and s5 plugs are different, so there's some splicing involved.

 

I have the a GTU but its wrecked. The engine still runs. The se did not run so I'am making it into a track car. so every thing is gutted. i just need to put the motor in and I was wondering if thats all I needed.

 

to swap an s5 into an s4 your gonna have to swap the whole engine with all the sensors wiring and the ecu, AND the rest of the wiring for hte gauge cluster, and posibly even more.