[Marshall V. Daut]

Point well made, "alexiskai". The way Ron Kelley explained it to me was to consider that if the holes in the head gasket fit around the studs tight enough to eliminate movement, you wouldn't be able to slide the gasket down over the studs. There is a slight looseness around the studs once the gasket is in place. As the cylinders fire, there is gasket vibration with a potential for movement. This is most critical in the very narrow area between the cylinders. Once the gasket starts "fluttering" from these vibrations, the gasket shifts and can blow out in this area. Old time hot rodders knew about this potentiality, so they would take a sharp center punch and hammer dozens of little craters into the metal in the block between the cylinders. The flared metal jagged edges would dig into the gasket and keep it from shifting. Of course, I doubt if the gasket movement could be seen or even measured. But according to Ron and apparently to those trail blazing hot rodders, Model A head gasket shifting is a real concern. Spraying sealant is just another way to reduce this from happening as much as possible.
Marshall