I hope you have better luck with the Tilton than I did. I ordered what was supposed to be the Superstarter for a Buick V6, shimmed it exactly per the instructions and then proceeded to put the flywheel teeth into the inspection cover when trying to start the engine. Rechecked again the shimming procedure- which was correct. I contacted Tilton and had to buy another mounting block. It too did the same thing. I figured since all the Busch cars were Buick V6s, there should be a mounting block that worked correctly. I even mailed Tilton a photocopy of the block dimensons from the Power Source book and am still waiting for a repsonse. That was about 8 years ago. It seems the Busch cars used a Tilton (or something similar) small diameter clutch with their flywheel, not a GM flex plate. Long story short, I couldn't get the Tilton to work and ended up using the LT1 starter. Let me (us)know what part number is engraved on the mounting block so I can sleep at night!
Mark