New oil pump

[JMBT]

Well I started her up for the first time today after the rod and main, and new oil pump job. (CM 2250, 764K) The truck runs smooth, but at high idle about 850-900rpm there is a “howling” noise coming from the bottom front end of the motor. When I get under the truck it sounds like it is coming from the brand new oil pump or at least right there on the oil pan. When driving I can only hear it when coming up to a stop. Oil pressure is normal idling and driving.

The gear lash was well within spec off the truck and also when mounted. I also pre-lubed it so it didn’t start dry. I did notice the wider gears of the new pump run at a different spot on the crank gear. Could that be the howling? Or did I get a brand new but bad part?? (I just read an article claiming nearly 30% of all new parts are bad) or maybe it is fine but it’s just going to be noisy?

Any ideas?