I'm trying to line up the pushrod guide plates on Edelbrock Aluminium heads. I understand that the guide plates are to prevent the pushrods from rubbing on the heads and to ensure proper valve train alignment. In doing this, I'm trying to get a small amount of clearance (1.5 thou or so would do me) between the pushrod and the guide plate, as well as get the other alignment issues right. Am I correct in trying to get this clearance or does it not matter that the pushrod rubs on the guide plate?