Trying to build a non-Mustang 4.6L using different year parts???

Alright, here’s the deal. I’ve got a ’96 Cougar with a pooched engine…..heads and all. Now, my question is, I’ve also got a ’94 Cougar and a ’92 Grand Marquis in order to pull the engines from. The long term plan is to either pick up a set of later model non-PI heads, port them and run some style of roots blower…..or, pick up a set of PI heads and do the same thing. My question is, that with all of the subtle differences between the different years, am I going to have any problems fitting the top end to either the ’92, or ’94 blocks, or would I be better off rebuilding the ’96 mill? I don’t plan on running any more that 325hp to the wheels, but I don’t want to buy a boatload of parts and find out they’re for another engine. I read the article posted in the sticky, at the top of the forum in regards to the different engines. But It doesn’t specify what car had what engine…just the year that they came out….and even then the info is a little foggy. I have no idea if which car uses a Romeo block, which uses a Windsor block, etc? Anyone confident enough here to call themselves a 4.6 expert that can steer me in the right direction?