[Formulajones]

The same guys that tell you a vacuum advance isn't necessary, lol.

I don't care what BOP says, it will absolutely leak past the cap mating surface.
The gasket only goes over the top, and the rear main seal only seals the crank surface. The cap area is metal to metal and it will seep oil through there over time.

Where people make a mistake is applying a glob of sealant there. Of course that can cause bearing clearance variances and obviously if too much is used it gets into places you don't want. All you need on that surface is a very small line of green loctite. It seals and doesn't affect how the cap mates to the block, won't affect bearing clearance or torque readings. Done.