If the lower control arms are level, and the ride quality is good, I would not change the spring, are you bottoming out on bumps? I would start with a sway bar, then if it does not improve, suggest an alternate wheel offset to remidy the wheel rub problem. The geometry of a MII is compromised if you have the lower control arms slanting downward due to too much spring height or too high of a spring rate, and ride quality will suffer!