I have a 12.5:1 511 street/strip car with the same bearing clearances and oil pressure as you. I was using the Amsoil 15-50 Dominator oil and pressures were where i like to see them in the comfort zone at 30psi idle and 65psi hot at anything over 2500rpm. I resently switched to the new Driven GP 15-40 and once hot pressures dropped considerably. Didn't lose much cold, but the Driven does not have good viscosity when hot. Gets thin like water when hot. I'm sure i get more flow with the Driven oil, but my comfort zone oil pressure readings are not there with Driven oil.