I built a 425 about 40 years ago and it was with a factory fresh block. Mains were about .0025 if I remember right. It has run 40 lbs cold or hot ever since, and about 12 hot at idle, maybe 15 cold. Just built another one. Mains were about .003 on this on. So far, oil pressure is about 2-3 lbs less than the first one. The engine doesn't seem to care. I don't race or abuse them. Someone with more performance experience could probably give you more info.
Tom