Well, I can tell you what I have since I just went through all of this. Stock replacement pump (American made). Key on and pump running, engine off I have about 16 lbs. That is going to be the bypass valve pressure. Running at idle I have about 14 lbs. and WOT I have 12 lbs.. All of this is measured on the outlet side of the filter with a 30lb. gauge mounted directly to the filter housing. If you are using a gauge with any higher capacity than 30 lbs. you will not get an accurate reading that low.

Those are my figures, others may vary.

Rick