Oil Pump Gasket?

That's it in a nutshell.

I never use them. Had one blow out and it resulted in a significant oil pressure drop. Never again. Once it blows out, it will usually continue to blow a larger section of gasket out.

I have never used one and even thought it's a thin, dence material, that's a pretty high vibration area and if i was to try one i would propably cheat on the high end of the torque spec. jmo