Re: Oil gauge jumping around
Typhoonran, you'll have to visit either RockAuto.com and browse the catalog, or visit/call your GM Dealer and ask for the replacement oil pressure switch. For the GM Oil Pressure switch socket, I'm not sure where to get it but you might try AutoZone/AdvanceAuto they tend to have the weird sockets..
Guys with wound up oil pressure gauges, this has been covered a lot of times (so search if you want additional advice) but to sum it up, I pulled apart my dash (plan a full afternoon for that, very tough to access some fasteners without losing them in a bottomless pit) and took out the cluster, flipped the gauge back to normal, and cut off the tip of a small nail, painted it black, and super glued it onto my cluster. Now it works perfectly like the factory intended and it cannot wind up anymore. Take a look, you can see my additional pin right above 80 PSI on my oil gauge. In the truck, you can barely tell it wasn't factory. (A perfectionist might use a drop or two of Testors Dullcote to remove the shine from the superglue.)