A rule of thumb for SBC does not really apply to our 250 inlines about for every 1000 rpm you need 10 psi of oil pressure.
IIRC Mike Kirby had told me 40 psi at 6000 RPM would be OK for oil pressure.
There has been others that have had the same problem with that high volume pump causing wear on the camshaft and distributor gear.

MBHD


12 port SDS EFI