I have a dilemma and need some advice. I have a 1990 4ws SI. It had jumped timing and bent the valves, so I had a mechanic swap the engine with a junkyard engine. He replaced all the maintenance items such as water pump, timing belt, plugs, wires. clutch, fuel pump, all gaskets O-rings, Etc. He had it running, then it jumped timing. Fast forward to today. I found out the junkyard sold me the wrong engine; a b20, instead of a b21. I'm on a budget and I've already blown all that money on the engine and parts....Will the computer work with a b20, what other parts won't work?