Cup and ball. You’re asking about checking length between the two push rods? If so I’m comparing overall length. Side by side. Push rod checker is a cup and ball, same dimension as my pushrods too. Maybe a little redneck but since I don’t have a caliper big enough I had both pushrods side by side and used a feeler gauge to fill the gap in until both pushrods were flush. .020” feeler gauge fit just right.
