Appreciate the info. I am doing the studs.

Just for my understanding, is there any data for why the 2 hole is better? Understand it is thicker but what would make that better that the original gasket size? It would seem to me that even with the original thickness the arp studs would provide the additional clamping required and you would still be using the gasket that was intended for it? Not questioning the idea just curious about what got those that are using the 2 hole to that decision? Thanks

Sent from my ASUS PadFone X mini using Tapatalk

_________________
2005 Liberty CRD, 245/75R16, OME CRD Springs front, OME HD rear

Look at the deck of the block for help visualizing this.

The liner has a small raised lip at the inner edge. On performance engines, this lip would match a groove in the bottom of the head, called a "fire ring" and could seal the combustion chamber from the gasket. We don't have that groove. If the liner is raised by shims from the factory to a point above the deck of the block, yet a gasket that is too thin is used, that raised lip might contact the bottom of the head anyway, causing the head to warp from the stress.

The sealing surface of the liner and gasket is actually the flat ring / flange outside of that raised lip. The actual top of the liner, which forms a seal that is about 3/8" wide pressing into the gasket. The combustion pressure directly "sees" the edges of the gasket's leaves, which is why good compression from the studs is so important. That pressure in the cylinders is 2500 psi or more, while the water jacket is only 16 psi. So if the combustion pressure can force itself into the leaves, it will find the water jacket very quickly and this is where the water loss happens.

Using the thicker gasket simply ensures that ALL of the compressive force of the studs is directed onto that wide ring, and the lip on the liner cannot possibly contact the underside of the head.