I have heard(to me) Terry say that the pushrod rubbing against the head is not a bad thing, it helps stablized the pushrod like a guide plate does After having to replace three single tapered pushrod on a customers engine due to the exhaust pushrods rubbing enough to not allow oil into the cups and burning the tips up I ground the head and the block to make sure the pushrods had enough clearance to rotate freely when the valves where closed Is there any reason to not grind the head or block to run the best pushrod?