oil pressure sensor installation

[gclark]

Hello,

I am trying to install an oil pressure gauge on my 1972 C10 with 350cid engine.

It has an idiot light which is wired to a pressure switch located next to the distributor. I want to keep the light.

Any suggestions for sensor installation? I tried to remove the plug located near the oil filter, but no luck yet. I think the plug is 1/4" allen screw, but not sure because it has a good bit of paint in it. I tried to remove it with a 1/4 allen wrench, but rounded it out some.

Thanks for any help.