While everyone has their own opinion on handling, I for one think the rear sway bar is essential to getting ANY car to corner well. The stock 4-leaf springs and new replacement 4-leaf springs are very limp and offer no real roll control at all. I have 5 leafs on mine and wish they were a touch stiffer for frisky driving. When setting up a suspension, I believe that letting each component do it's own job is the only way to go. For example, spring rate should be just stiff enough to keep the suspension from bottoming out, not for roll control. Sway bars should control body roll, but need to be properly sized. Mine is a 3/4 adjustable and is set on full stiff. As for oversteer, it hasn't even been an issue. My fastback with 15's on it will out-corner my '88 GT with 17's and sticky tires on it and that's saying something. Personally I think the "sway bars equal oversteer" thing is a myth. Any car can be made to oversteer if you're rough with the wheel, brakes or throttle, the suspension needs to be tuned to the driving. I currently have 5 cars in my household, a 2004 F250, a '97 Suburban, '88 GT, '69 Corvette and my fastback and all but one came from the factory with a rear sway bar. Think that's an accident? I was once told by someone here that "our early Mustangs weren't designed to use a rear sway bar". Bullstuff. They weren't designed for radial tires, either, but who here is using bias plys? Until someone shows me in person or with lap times on a track how on earth their Mustang could possibly get worse with a rear swaybar, I'll have to assume that I'm doing it right. After all I've driven my car with and without a rear bar I can can say with all certainty it's much better with.
