recommendation oil pressure switch

I agree, they don't need to be tightened like you're holding down an ocean liner.
I had one stop working for me on a 79 300 w/a 360. It never leaked, just read 0 oil pressure. It turned out a PO had wrapped the pipe threads carelessly with Teflon tape, and a booger of Teflon tape unwound and covered up the hole so no oil was getting to the diaphragm. Removed tape, rewound it in the correct direction holding the tape back a few threads from the end, then reinstalled. problem solved. Whew! I was sure glad I didn't really have 0 oil pressure.