Firm feel 1.12" bars, 300 lb/in wheel rate. I don't remember what I calculated for the rating on the Hellwig bars, it was just a generic number based on the diameter. I use the hollow Hellwig a-body bar (55906) and the solid rear 7/8" E body bar. I wasn't going to go with custom bars so I wasn't too worried about calculating the exact numbers for the bars. I run 120 lb/in AFCO rear leafs with those bars.
Actually the factory rear springs are much closer than the factory torsion bars, which are massively undersprung. The stock XHD leafs are 110 lb/in, the Mopar oval track springs are 120 lb/in and work great with a rear sway bar. Too much more than 130 lb/in in the rear and you have to drop the rear bar otherwise you get too tail happy.
And that car would have been running 1.24" torsion bars at minimum, and maybe would have had the anchors swapped out for c-body pieces to run an even larger diameter depending on the set up.
