Mike, i hear ya , im running same tire size but in 19 s. with fully adjustable TPC racing sways set in the middle to be as neutral as possible.. the roads in PA suck and it gets really bumpy in the car at times.

4 from softest on the front, 6 on the back. Stiff, yes but cornering is great. My setup felt like crap through the steering wheel until I had a good alignment with corner balancing