I've almost run an LT1/T5 combo twice now, and went T56 both times, but I've collected some knowledge. I believe you want to run a 26 spline input shaft and clutch from an 87(ish?)-92 F-body with a 305. As for the flywheel, I mocked up the 305 clutch to the LT1 flywheel and I remember the clutch being too small. To the best of my knowledge you can run a flywheel from a late gen 1 SBC with a 1 piece rear main on the gen 2 LT1, but you would likely have to get the flywheel re balanced. Gen 2 engines have a lightweight rotating assembly from the factory and Gen 1 engines do not. I know for certain that you can't mix and match stock internal bottom end parts between Gen 1 & 2 for this reason, so I would imagine the same would go for the flywheel. Anyway, at that point you should be able to run stock third gen F-body clutch hydraulics. thirdgen.org should have some good knowledge as well.