What is the part number for MSD small block dizzy cap

Thanks for that. The issue I am having is the cap moves around when I have the two legs that attaches it clamped.
Is there some sort of sweet spot/ register/ notch somewhere I am missing…. Cap shouldn’t move when it’s attached. You can grap the cap and it literally feels not seated. Moves around putting your hand on it.
Getting an intermittent loud backfire, thinking this might be the culprit?