Use the block, crankshaft, pistons, and connecting rods from the GM minivan. Everything else comes from the Fiero including heads, intakes, exhaust, timing cover and water pump, oil pan, fuel injection system, and distributor. You might want to swap the camshaft or install a new (Crane 2030 IMS) camshaft into the Fiero. Replace all the seals, rings, and bearings and you might want to add a new oil pump, timing chain set, oil pan windage tray, and variable fuel pressure regulator.
List of the cars with a flywheel / flexplate that you can use to replace the exisiting one.
You should look for a 3.1 from 1990 - 1995. Make sure you get the minivan, the 3.1 from a car is a different engine.
[This message has been edited by Steve Normington (edited 09-08-2004).]