Well I just got some prices on all new PI valves and springs. How much should I expect to pay to get these installed in a npi head? I just called the machine shop and he told me that the head is part of the seat and if he ground the seat, there wouldnt be one anymore. Are PI valves that much larger than the stockers? Would I also need new valve seals? They gave me a price of $75+parts/head for a 3 angle valve job. I think this is a pretty good price, although I can't imagine what parts would be involved. I'm supposed to bring them the bare head to get that price which isnt a problem seeing as how the heads are sitting in the floor of my room. Would the NPI valve springs still be good? Thanks guys!