n/t

No just the ECU and wiring harness, I believe. What kind of car are you gonna swap the engine in to and what is the engine to be swapped?

A 90 vert engine into an 87 SE.

There are two ways to do it. You can either swap in the '89 electronics or swap the '87 injectors/OMP etc...out of the old engine.

Whats easier and would work better?

the simplest way is to put all of the s4 stuff onto the s5 block



mike