Early A Body Sway Bars

Okay, maybe I'm terrible are researching this but I can't but a single rear sway bar for my '66 Dart.

The only one I know of so far that will fit is a 7/8" Hellwig adjustable, p/n 6907 which Dave from Hellwig said will fit.

Does anyone else know of any part numbers that will fit the rear of a '66 Dart?

Another question - if you have experience with installing one will I need different mounts or u-bolts if I eventually upgrade to a 3" diamter axle housing as opposed to my current 2.5"?

Thanks a lot!