tpis15

I recently put a low mileage vortec 350 in my camaro. In the process I put a new lt4 cam and new lifters in the motor. Now I'm having a problem with my lifters ticking on a cold start if the car sits for a day or more. If I pull my fuel pump relay and crank the motor until the oil pressure builds up its fine. I have noticed that it takes about 10 seconds of cranking the engine for the oil pressure to start to build up. Is this normal? Could my oil pump not be priming immediately? Could it be bad lifters? Any other ideas?