Hi I am planning a performance upgrade for my 75 Dart Sport with a 318 and I need some advice. I havnt done any engine mods yet, but I did have dual exhause installed. I am thinking of swapping the stock heads for the late 80's "302" heads, putting in a 340 cam, a 340 4 barrel manifold, with around a 600 cfm carb. I am also putting in headers. Now is there anything about this setup that would go wrong for some reason, or something that I dont know about. Also what sort of power boost would that give my car? I'm a daily driver and I don't want to lower my mpg too drastically, but the reason im planning this is for a power increase.