Y07 -- T/Anks for the update.... next you'll be getting the front dbl-adj Viking shocks?
Question -- where are the measuring points that you're indicating for ride height?
As for your question on 60-series tires/bounce, there may be some concern... the taller sidewall initially gives more forgiveness to impacting any road hits (pot holes, etc). I suggest you try different psi setting for the tires. On my own Challenger, when I drive on the street/hwy with my 15x8 minilite rims having 255-60-15 fronts and 275-60-15s rear (all 4 BFG T/As), I find a pretty good psi setting at 28 f, 26 r (sometimes 30f, 28 r). My suspension is very stiff (1.24" dia torsion bars, 225#/in fiberglass leafs having 5" uncompressed arch)... and I'm using old red Koni D shocks that were rebuilt a little stiffer... set at full stiff front, ~2/3 stiff rear. The ride quality on the street/hwy isn't bad t all (street doesn't really count... low speed and sometimes a little rough for a short time/stretch... I prefer the hwy driving as the roads will typically be much smoother)