the P7100 needs more fuel supply than a ve, the lift pump actually helps feed the piston in the ppump, the ve and vp44 both have internal pumps that will pull fuel in the event of a lift pump failure but they are weak at best. some 24v cams do infact have the lift pump lobe. the block mounted lift pump is good for about 500hp. the reason so many people go to an electric lift pump is the flow is stable and the pressure can be adjusted to feed correctly.
Ok another question, is there any issue with having 30-40 psi of fuel at idle? what about 60 psi of fuel at idle? the P7100 injection pump has a fuel return, correct?