Thanks for the mock-up suggestion. I bought the parts and mic'd the height. My install height was 1.820, which is 0.120 taller than needed. I was amazed at the thickness difference between the Comp Cams retainers and the factory retainers. It looks like I'm going to swap my retainer locks for -0.050 locks and add a 0.060 shim to make up for the distance. But atleast I don't have to machine anything. Thanks again for all the help.