Roush front springs and mating roush shocks makes for a very rough ride on crappy roads...extremely stiff. I sat on it, doesn't budge. The roush front spring is 1/2" lower than oem. Roush front shock lower's it another 1/2". I ended up busting a front roush shock, so went to oem front shocks....but still use the roush front springs.. which are 20% stiffer than oem springs.
The Roush springs and shocks, the 427R stuff, is bearly stiffer than the stock V6 suspension as far as ride quality goes. And works way better on track. I can't understand why you would call that a very rough ride.
Now my 91, with 800lb front springs, Koni yellows, and all rubber bushings removed in the front (delalum zero deflection control arm bushings) has a very stiff ride on the street. I should soften this up for selling it. lol