your going to have a problem with the wiring. you will need to re-wire the whole car if you want to use that new 90 ecu, or you need to buy a 95+ turbo ecu. the easiest thing to do would be to swap a 7bolt engine in. you can get them for $500 for a good engine with a head(atleast where i live) i think it would be easier to find a junkyard and buy a front clip off of a 2g turbo.