OK...so I dropped a salvage yard B18 LS motor in my DA...oil light came on, would be DIM...FLASH or be on STEADY....MIGHT almosy go out but not really. Note that I drove it like this for a coupe days...aside from off and on rough idle ( which I have had since droppin in the motor ) the car still runs great, is very strong and doesnt smoke. Did much forum searching and decided to install a gauge. After 15 min or so of idling...it seemed to be happy between 10-15 psi, when driving..at 2500 rpm it runs about 40 psi and doesnt seem to wanna go over 80 psi, even in higher rpms. Once I drove it 10 min or so, the pressure dropped to about 5 at idle. So.....do I have a problem? Or is the better question, how much of a problem do I have?

Oil level is good btw