Right now I own a 94 4.6 LX Thunderbird with over 160K on the stock motor that's in it. Something broke or came loose on the passanger side head (loud metal to metal clank under the valve cover over 1400RPM and a continuous tapping at any RPM) not to mention it burns the hell out of oil and runs like **** even before the problems with the head started. Eventually I want to slap a 99GT engine with a supercharger on it but what should I do in the mean time. I was thinking of having the engine rebuilt and putting PI heads on it instead of fixing the old ones. My questions are can you swap the heads without swaping the new intake manifold too? or if I can't afford that can I just swap the new PI intake without putting the PI heads on too? Thanks.