I need to find an oil pressure switch that has two terminals and has a closed circuit when pressure is present. The reason for this being is that i need to hook up a fuel pump relay for my car instead of having the pump solednoid wired to ACC. I have an older 350 block from 1974 with drivers side dipstick. I need the switch to go into the oil plug just above the filter. If anyone knows exactly what this switch is called at a parts store or what the thread size for the switch is it would be greatly appreciated. Thanks -Bob

 

You should be able to use the oil sensor from a later LT1 engine. They are mounted via a 1/8-27 NPT connection, have a resistive output based on oil pressure (which you may or may not use for an oil pressure guage), and also have a pair of N.O. contancts to act as the auxilliary fuel pump power switch. Any parts store should have them. The typical closing pressure for the switch is 7 PSIG, and opening is 4 PSIG.

 

I wasnt exactly sure what to ask for at the parts store, and even if i knew what it was called i wasn't sure of the thread size, thank you Vader. -Bob