I thought that too, but they're in the exact same location when compared to my '73 340 Dart, but to be on the safe side I ran a solid bead of weld around the sockets to prevent a future twist/failure since the factory welds were crappy at best anyway.
How would I ID a set of drop spindles? I don't have any spare spindles laying around to compare with at the moment, they're all on the cars.
When I turn the adjusters, I get some ride height, but over the course of about a week it slowly settles back down to the same height, even though the sockets haven't spun any and the adjusters haven't slipped or backed off. Eventually it reaches the end of the adjuster bolt and I give up for the year (on going for about six years now) and the following year I'll put another set of bars in the car and start the process over.