Rear Diff. Bearings- Where should I Order from?

I've bought literally hundreds of parts from Rockauto over the years...and I do have standards as to what parts I purchase. The only problem I've had with their parts is one time when I purchased a set of closeout struts for a Trans-AM and they were old and one was seized, however, they took them back and refunded my money without any question. Rockauto doesn't do anything different than any of the other major part stores. I once new a guy that worked with AC Delco. Did you ever wonder why an AC Delco part, like an alternator, sells for so much cheaper at a store like Advance Auto Parts than it does at a dealer? He told me that whenever the came across an alternator that failed testing on the line, they would pull a given number of alternators made before and after the failed part and sell those of to stores like Advance Auto and Autozone. There may or may not be anything wrong with those other alternators, but it does limit the chances of a defective part ending up in one of their preferred sellers, like GM dealerships. You get what you pay for...or, at least, hope to!
I prefer not to buy Chinese parts, too, but when even brands like Moog start selling parts under their name that were made in China, it can sometimes be a challenge to find parts that weren't made there...and even harder to find parts that were made in the USA. For example, just try to find a radiator (other than all-aluminum performance radiators) that isn't made in China. You might find one that is made in Vietnam, Indonesia or Korea...but will be hard-pressed to find one that is made in North America. Even most of Canada's Spectra Premium radiators are sourced from China. I'm not saying this is something I am happy about, but it is the current state of affairs.