The 383 I dynoed with high oil pressure using the 10552 ST oil pump was exactly what I thought was the problem. The bypass valve was to long and not exposing the complete bypass hole. I also have another engine with the same pump same problem.
I don't understand why I have to there home work for them. They told me not to take the pump ap
art it would void the warranty. I said really.
I have used probably 35 of the10552 pumps with zero problems. Now they said the 10552 ST they did change the cover HMMMMM
Here is a link to the dyno run
Good customer Jerry Brighthaupt saw my post on FB and took his 10555 ST pump apart and called me and found less the half the bypass hole was exposed. He was just getting ready to put the pump and pan on one his circle track engine. He was going to shorten the valve 3/16 of and inch which will cure his problem.
A big shop near him stopped using those pumps because of high oil pressure.