It may have been the fella didn't give enough clearance when he put the head together, but don't use the positive type seals on at least the exhaust, I tried it and had to pull the head and get new valves and guides after about 300 miles when they all started sticking open and dropping the pushrods. I left them on the intakes though. They are only meant to CONTROL the oil, not wipe the stems smooth clean, at least that is the theory as I understand it.
