Stock oil pan and HV oil pump?

Test everything! 426 small block with high volume pump running pressure fed pin roller lifters with a 8 qt oil pan. Put just 4 qts of oil in the pan and primed the engine with a speed wrench. 65 psi and ran out of oil in the pan and started sucking air. Blocked the oil feed holes in the lifters and primed the engine with a speed wrench. Picked up 10 psi oil pressure and never ran out of oil still using 4 qts of oil in the pan.

Not saying anything was bad, because with the full 8 quarts the engine spun to 6700 rpm and never lost oil pressure before blocking the oil holes. But when hot rodding and your gut tells you to check something, check it!