reviving my 83 firebird

ok so here is the deal have an 83 firebird that had a 2.8l V6 originally i drove the wheels off of it until i broke the crank shaft and pretty much destroyed the motor. Been working on it for a couple of years now and almost done but i have a dilemma my 5 speed transmission is out of a 1983 trans am and was originally bolted to a 305 HO i got the flywheel and pressure plate that came with the motor but the current motor I'm installing is a L99 (4.3L V8 identical to a LT1 but smaller boar and shorter stroke but should still have plenty of power for the car at almost 3 times stock though) outta a police interceptor and i need some help finding a flywheel that will work. I've been told of a couple of options a) order a new manual flywheel for an LT1 and then get a new pressure plate to go with the fly wheel and use the clutch disk that matches the tranny or b) i was told that a flywheel from a Gen 4 305 or 350 car or Gen 3 after the diameter of the crankshaft was changed in the late 80's would bolt to the motor and should match with the pressure plate i have. Does anybody know for sure if either of these will work or know of somewhere that i can get some kind of conversion that will help me with my problem?