Re: Need help with gasket-
I think the "bump" is meaningless. Stick it up on the block, if it fits fine use it. If want trim it slightly but I'd just assemble the thing. The O-ring is what stops any leakage, Hopefully. All the gasket does is keep filtered oil and unfiltered oil separate. Note: lube the o-ring before the install and DON'T use any sealer in the gasket. Chances of getting some into the motor are to great and there's nothing to gain.
HTH