The problem is you, using air shocks.
Pinion snubbers are a bit different than traction bars. Traction bars were made to be installed on Chevies where the leaf spring design resulted in massive axle hop. There's two for a reason. They're an attempt to emulate the Chrysler design that was built into each and every leaf spring set.
The pinion snubber is a legit traction aid that was only installed to limit travel and aid weight distribution. That's why only one is needed.
Mopars of the era don't have axle windup issues like the Chevies do. In other words: The pinion snubber completed the system but wasn't really required unless racing supported the need for that approach. It was great for street cars of the day that saw some strip use.
The traction bar was added to try to resolve inherent deficiencies in the (Chevy) system. And like everything else, just because it fit their car, Mopar people felt the need to put them on their cars, too. They didn't accomplish anything, but added some little needed street cred.
