I bought a 83 c10 last week and the guy I bought it from said it has a 350 crate engine, and I looked and he wasn't lying, so I changed the oil, new spark plugs, cleaned the carb (edelbrock 600 4bl), new edelbrock filter and put some fuel treatment in it, runs better than it was for sure, but I noticed when I drive down the highway the coolant heats up to around 190-200 and when I come to a stop the oil pressure drops down to below 10 psi and dies unless I put it in neutral I can keep it running, I'm thinking it's the oil pump not pumping enough oil, or somethin to do with the timing or distributor, what do you guys think? I need one help on this one

 

There isn't one thing wrong with it. Hard to diagnose several issues like this. The 190-200 temp isn't bad. The less than 10 psi oil pressure is bad. Have you confirmed the gauge is working.

Did it idle fine before you did a "tune up"?

 

You probably need to check timing and adjust the carb. You could also raise the idle. The oil pressure is a little low but does the motor make noise like it is starving for oil? You gauge could also be off. If the motor isn't making any noise you are probably fine.