My 360 sounds like a sewing machine

IMO that oil is a bit too thin, I've also personally not had good results with Castrol oil but I don't think that's your issue.

You mentioned there might be too much oil in it, if it's a quart over you'll definitely have noisy lifters from the crank whipping air into the oil.

Lastly I don't know if it applies to the LA roller cam engines but I know on Magnums the spec for lifter preload is in the .080-.095" range, much more than a typical flat-tappet or aftermarket roller cam and lifters. They run fine with less but I've heard they do make valvetrain noise like a solid cam when set up that way. I put my 5.9 Magnum together with around .085" preload on the factory lifters and there is no valvetrain noise at all.