Find a local rebuild shop and start taking every one of your alternators and starters to them. Keep them in business. You will get a much better product. And the cores don’t get thrown around all the way back to the China (CCP) Rebuilders.
Totally agree, use your local rebuilders. Keeps their doors open and you get a better product. Also, you can "date code" the products by bringing your own cores in. Many times, a better price.