No oil pressure at idle

My engine builder told me if I put a hi volume oil pump in with the original oil pan I would suck the pan dry 360 with original 5qt. Pan is this true after reading this thread and seeing people putting in hi volume pump's

I run a HV pump with a stock oil pan on my 360/408. Never have I had an oil pressure problem. 70psi cold idle, 40psi hot idle. Bearing clearances are in the .0028-.0031 range and timed oil to the heads (not a fully grooved cam core).

HV will provide more PSI at a lower RPM than a standard volume or a HP pump. The bypass will open sooner on a HV. Engine masters did a whole episode on oil pumps and comparing HP, HV, super-HV, and aftermarket vane pumps. The absolute highest flowing pump used about 4hp more than the stocker. The HV pump provided higher idle pressure than a HP, the HP provided higher pressure only after about 2k rpm IIRC (pump has to flow enough to get up to bypass pressure).

If built with clearances on the tighter end of stock, I'd run a stock pump. If running more clearance, which is a good idea, a HV pump is a no-brainer. A HV pump can also help a worn or high-mileage stock shortblock.

An oil pump won't suck a pan dry - oil drains back quickly in an engine, and the passages and filter can only hold so much oil - it has to go somewhere and there's few places other than the sump for it to reside. If all the oil is staying 'in the heads' there's other issues.