54 GMC:
To the best of my knowledge :rolleyes: , all of these sixes had MECHANICAL oil pressure gauges up into the '70s.
There should be a brass block on the back side of the gauge that's tapped and threaded for a small fitting nut, and a tiny steel or copper tube that runs through the firewall and connects to the engine, on the left side for a Chevy, on the ... right (?) for GMC (?).
I think the only engines that had an electrical type sender were the ones with idiot lights.
