I posted yesterday that my 440 lost oil pressure after an oil change and had to be towed home. At the advise of people on this forum I have removed the distributor and inserted a 5/16" tool to operate the oil pump. I am turning the shaft counter clockwise and feeling some resistance. I have the valve covers off and I can hear the oil gurgling and hissing coming from what sounds like under the intake manifold. Watching the oil gauge it doesn't appear to move or maybe just slightly.
Has anyone done this that can tell me if the gurgling and hissing is a normal sound?

Thanks