I was curious on how much wiring has to be changed for swapping a v6 into a 4cyl. if its just the front or under the dash to. I'm doing it to a '91 cavalier rs. I have a 88 or 89 z24 donor for wiring. the motor is coming out of a 3.1 lumina euro. I have the whole wiring on it to. I was thinking about wiring the euros second fuse box up and running its ecm. but I dont have a wiring schematics for it. Any help would be appreciated.

The engine harness and ECM for sure. I'm not positive on the gauges connector pin outs for a phase 1- phase 2 harness swap. You would have to check out the wiring diagrams at V6Z24.com. You won't need anything from the Lumina but the engine. Why would you add another ECM?

i just wanted to say thank you for your COMPLETE break down of this install. but i have one more question, i have a 91 2.2 auto i need a tranny now but so i wanted to go ahead and swap the 125c for the hm282 now ive read everywhere and they say it almost bolts up and of course no wiring. i also read that the shafts will fit but i need to know if they are too long? please respond when you can. thanks alot. also if anyone could help me with finding a shop in the atlanta area.

There is an auto to manual swap How To on v6z24.com. It tells you everything you need to do. There is some very easy wire splicing required, and there are several threads about what axles you can/can't use there as well.