Ok, so my buddy has a '91 Vert NA 5spd N353 ECU that is believe to be the root of his issues right now, and I've got a '90 Auto GXL ...I haven't pulled the ECU on it yet so i dont know the code, but would that be able to be swapped in? I believe the automatics had different ECUs, but since its going into a manual and not vice versa it should work, right?

yeah, if you're going at to mt you might have a code, but it should run.

That's what I was thinking, I just needed a 2nd opinion. I'm going to give it a shot. Thanks man!