just rebuilt a 305 out of a 88 firebird formula. refurbished heads crank, all new bearings and oil pump. 10 oversized rings and all the normal seal and gasskets. Any way heres the question, when she first started she had awsome oil pressure. Now the gauge only reads like 20 psi when Im at 2000 rpm when im at idle its like 6 psi according to a manual gauge. The engine now has 1700 miles on her I can lifter one of my lifter tapping. What are the odd that the pump could have messed up verses that I am on my way to destroying a bearing or two. Oil pressure reading was taking at the top of the block. I put a stock pump in the car. I also notice that if I rev the car up pressure will come up but as soon as I back off the pressure drops real low. Could this be a weak spring in the oil pump? Any opinion would be appreciated????????????

Kenny