Okay, I am very new to engine mechanics, so if I sound like an idiot, forgive me. I have a 65 chevelle. It has a 65 dated 283/327 block that isn't original to the car. The heads are 283 heads dated 1960. I was thinking about getting some 65 double hump 327 heads. What do I have to do in order to swap them out? I don't mean step by step procedure but what else do I need other than the heads? If I have a garage do it, what is the cost I am looking at?