Any disadvantages to running a vaccuum pump? (for oil)

I run around 15"Hg of crankcase vacuum street/strip. Main seals installed backwards, no problems. Also no leaks. Even had an incident once where i melted a sight gauge tube in my oil sump, didn't leak oil until after I turned off the engine.

Oil pressure on the gauge does go down as vacuum goes up, but that's mis-leading as the oil pressure gauge is measuring the difference between oil pressure and ambient air pressure outside the crankcase. If the oil pressure gauge was located inside the crankcase (referencing crankcase pressure instead of ambient), indicated pressure would not change. Basically the loss of gauge oil pressure due to crankcase vacuum is an illusion.

Grant