When I'm cruising and not beating on the thing the oil pressure is at 30, when I get after it my oil pressure drops to 0. I have only driven this thing for about 100 miles, I think the sending unit is bad or the gauge is shot. What is the best way (easiest) to check the actual oil pressure? If I need diagnostic tools please let me know where I can find them.

The car is a 92 305/tbi

 

To avoid the obvious check the oil. sound like it is running out. I am sure you have done it but thats what it sounds like

 

just changed the oil 100 miles ago

 

my opinion would be to by an aftermarket gauge and try that. then you will have a new sending unit and working gauge for sure. if it still does it then there are other issues

 

take a valve cover off

when the oil gauge says 0 there should be no oil coming out of the pushrod tubes

if there is oil coming out then replace the sender