That's a lot of work. I'd recommend not doing this swap unless you intend to use a high-performance transmission and take this car to some serious performance events. In all honesty, that third generation Z28 is probably beautiful but not worthy of this sort of investment given the current value of the car. If your cousin doesn't have a ton of money to throw away on unexpected expenses, this is a terrible idea.
PENSACOLA PEOPLE, PM to trade the following for my stock SS parts: VR Heritage Grille, used exhaust, used intake, ported throttlebody