Stop in for a cup of coffee
Well, I finally found the information I was looking for (wasn't easy to find)
The 002/003 rear SS leaf springs I have are 150 lbs per inch spring rate. The .920 front torsion bars are also 150 lbs per inch. Perfect match!
I also debunked the "SS rear springs will make the rear sit with one side higher than the other" myth as far as I'm concerned.
According to Mopar, that happens
only when using the P4120863/P4120864 combination and they call it out specifically. All other SS spring combinations are level at "standstill".
Here is the torsion bar spring rate chart for anyone who is interested...