My take on the oiling system crossover tube for the small block

Duane said

I agree with what you are saying but imho he should verify that he has 50 psi at 6,000 rpm and not 36. I think the line pressure reading dropping at higher rpm is indicative of an excessive leak.
The other reading stays steady at 49 psi regardless of rpm but the line pressure reading even with a bum gauge drops as the rpm goes up. That does not look right to me imho unless you have oil gushing out somewhere like lifters.

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Just the model in my head....I definitely can see the flow increasing at the rods with RPM, as centrifugal force throws it out; it's like a negative pressure at the edges of the rod bearings. I can perhaps also see flow increasing out of the lifter area even if the clearances are snug. Either way, increased overall flow with the resulting few psi drop from 3k to 6k RPM would not surprise me at all even with everything being tight; operating conditions that effect oil flow are certainly changing with that much change in RPM.