This set of a-arms came off the same car, it’s a car that a front clip has been added for accident repair in the past - and I just noticed a difference. I was wondering
If someone could offer an explanation for the difference. The arm on the top has a sort of raised “notch” created from the ball joint hole.. the bottom one has a “tab” like feature instead. I was planning to weld up the hole/tear in the top arm and started wondering if the bottom one is even correct or complete (maybe the tab should extend upwards? ). Anyone got a good idea what’s what here?

They made a small change at some point so one of the arms has been replaced with a later one. Probably from accident repair. They function the same.

Good, thanks ..

Top one is the early version. To keep the ball joint from spinning they welded in the tab in the lower version.