Buying ACDelco, Motorcrack, or Mopar does NOT guarantee OEM quality. Remember guys those are just brand names now. Yeah like fifty years ago if you bought and ACD part it was likely OEM from the factory. Not anymore. Yes, the OEM’s use very high quality parts from all of the major suppliers BUT said parts are built to very stringent specs and only for factory production line. So Borg Warner, Moog, Monroe, Raybestos, etc obviously make aftermarket parts but more likely than not they are NOT the same quality as the OEM order. It’s up to the buyers for the car manufactures. Once the production line is finished than the high quality parts orders are finished.
Now as far as the brands, they have a reputation to maintain. So yes, buying ACD, Motorcrap, and Mopar will generally indicate you are buying a high quality part. As you see with ACD, they also have a “value line” Of cheap CHICOM junk.
If you are a planner, there are vendors on eBay that sell genuine OEM parts that are assembly plant leftovers. For example, one was selling brand new OE strut spring combos for $130/ea.
This is one of the vendors:
https://www.ebay.com/itm/192927265982