Bitter learning curve. Absolutely DONE with carburetors!!!

My Imperial's 440 is waiting for me to take the time to change the pump - it leaks into the crankcase too. **** happens.
My rule of thumb on a new engine is noises are not a big deal coming and going. But if the oil pressure changes either at idle or above idle - pull it and inspect. Waiting just lets the problem get worse. Catching it early enough means little to no machining. I would check the crank end play first, you might have a thrust going bad, but I'd be figuring on pulling it at this point.