ORIGINAL: recklss83

Ok here's the deal i just bought a 95 mustang gt. i found it on ebay it was 20 mins from my house so i picked it up. the guy i got it from is a farmer using it for his wife to go to work. the guy he got it from appartently did a lot of work to it. i know its a 5.0 h.o.but its not stock its got a fender well intake and true dual exhaust but beside that i dont know what else is under the hood he had a bbk performance sticker under the hood but i dont know what it could be? the odometer reads 152k but i dont know if the engine has those miles or if it has been rebuilt, or what other parts are in there, cam, heads etc. short of tearing down the engine how can i figure out whats on there. and another thing even if i do go into the engine how will i be able to tell the difference between a stock and aftermarket part?
i eventually want to go with forced induction i was planing on getting a low milage block and building it up from there anyone have any advice on where to start and they beast way to get to forced induction (parts wise)