Some of these brands just rebox an OEM supplier’s part, so would they really go through the trouble of having inventory of two separate parts for the same application? As an example, I’m looking at an upper ball joint for a 1998 Toyota 4Runner and the AC Delco 46D0116A (economy line) appears to be physically the same as the AC Delco 46D0116 (daily driver line) but it’s half the price.

https://bobistheoilguy.com/forums/threads/rockauto-economy-vs-daily-driver-vs-premium-parts.326661/