Oil pressure gauge with single terminal warning light?

A side note for those changing an oil pressure switch, consider a 3-terminal switch (1970's Chevy?) which is wired to disable an electric fuel pump if oil pressure is lost, for safety. I did that in my 1964 & 65 A-body. One terminal goes to the Starter Solenoid ("S" terminal) to run the pump ("P" terminal) while cranking. Once running, "P" is powered via the ignition wire ("I" terminal) if oil pressure is up. From memory, but google for much info and PN. Same 1/8" NPT thread. BTW, the slant six oil port is 1/4" NPT as I recall, requiring a reducing bushing (or correct sender PN).