Remove oil pressure switch next to and below oil filter housing. Use a deepwell 1 1/16" socket. Screw in the auto meter adapter which is 12mm 1.75 male thread to 1/8 npt female. Add a 2" 1/8 npt extension. Take a 1/8 npt female t fitting and drill out the side hole and retap for 12mm 1.75. Screw it onto the extension. Screw your stock oil pressure switch onto the retapped threads, and your oil pressure sender to the end of it. Always use teflon tape or a sealer on all threads. Hook up wires and your good to go. (I had to extend the stock oil pressure switch wire several inches for it to reach where I put the switch.

 

Does not make sense as written.

I assume you are installing a oil pressure gage (however you spell it)? If so, you should elaborate.