Here is one of the real problems, there is no room for a mike so I used calipers, there is just .150" of material in this area to seal the HUGE vacume in the port! I bought the rotating assembly new, freshly machined and balanced at Diamond Elkins, from a long time friend of Dan Manchini, Butch Elkins, and a long list of famous Mopar racers/builders. In discussing this with him, he relayed stories about racing in the "High Roller Club". This group would race, flat out from Detroit to Chicago, stop, then race back! His HEMI Charger would see 6,800-7,200 rpm for hours! Oil consumption was a problem! One of his buddies, installed a small "O" ring around the stud in this area to prevent the gasket from taking all the abuse!