I ran them on my 3750 lbs 1970 e-body. They work great on a really smooth road. Out in the real world, they are nothing short of brutal on ride quality no matter how I adjusted them. Same thing with SS springs and a pinion snubber adjusted to the Mopar Chassis manual settings.
I now run a pair of passenger side, 2800 lbs SS springs with properly adjusted slapper bars on both my '70 E=Body and my 3700 lbs A-Body convertible. Best ride quality and traction I ever had in over 4 decades of trying to figure this out.