I have wired them with permanent wiring on an oil pressure switch, but also a manual push-button switch to activate the pump prior to the presence of oil pressure.

I don't use regulators. The carburetors I use (its an 8 cylinder, not a 6) can be modified to withstand higher fuel pressure, and I have modified them to do so.

Jon

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop