Just remember that oil pressure is determined by restriction (i.e. Clearances, orifice diameters, passage diameters). With that said, a motor with "proper" clearances should have the same oil pressure with a standard pump as with a HV pump and not any more flow. If a Cleveland has excessive loss before the crank, causing pressure loss to the crank(i.e. loose lifter bores and or top end), (the pressure gage will not tell you pressure at the crank), a HV pump will "hopefully" out flow the loss before the crank and maintain oil pressure to the crank(Bandaid). If there are excessive clearances before the crank, it may out flow the passages to the crank and never mantain pressure to the crank, even with a HV oil pump. A High pressure spring will only raise the pressure at peak restriction and will not provide more oil flow(not a fan of this). I do strongly advocate Lifter bore bushings, T Meyer cam bearings, and "Winks" oil mod. But on a build like this, I do believe, at minium, that all the lifter to bore clearances should be checked(dial bore gage, top and bottom of bores)against the lifters you are using. For a mild build, a little loose(top of the tolerance) use a HV pump, sloppy(over tolerance) use bushings. Correct me if I'm wrong!