1992 Firebird Engine Swap

I am looking at buying a 1992 Firebird with the 3.1 L engine. But in the future i would like to be able to swap in a 5.0L into it. The question I had was how much if any modification does it take and how many new parts would i have to get that wouldn't work with the 5.0 that did work with the 3.1? I am pretty sure i would get a crate engine from a parts store so thats what I would be started with. Thanks for any input.