my brother checks the radial first, (have to as we run .0030 clearance. It is a racing engine) The pockets are on the pistons (custom CP) are small side due to using them with a few different heads / valve sizes. He has a valve stem cut to a point, bolts the head on, then puts the stem through the guide to pips the piston top for each valve. He pulls the head, then checks the valve center to edge and the pip to side of pocket clearance. I learned how to fly cut them on the mill last week. 8 pistons and 32 pockets later…. Fun times. Still have the piston vise on the mill. I’ll post a pic tomorrow.