i have ported 5.3 heads on my motor and don't really feel like pulling them off and i'm not sure whos heads they are. when prc or any other company ports there heads to they cast or stamp there heads with a part#? i prob have to make a few phone calls but any help would be awsome. the cam was pulled out and the numbers were ground off the back, it just says 114+4. the heads originally had the early comp dual valves springs on it(the cheasy thin inside spring) but they broke on me.