Spoke to a shop about checking over a set of 66 401 heads for a stock refreshening (if needed) and they claim experience installing hardened seats and brass valve guides. But my understanding is that the seats are a common No-No and the better guides are cast iron. So I wonder how much expereince they actually have with Nailhead heads. What is the general concensus on valve guide seals and on which valves? Anyone know of a resource around Milwaukee/Sheboygan, WI to have my heads freshened up? Thanx for any help!
