A BAR TO THE RESCUE

Do you need a rear antisway bar on your muscle car? If you're praying when you launch, maybe you do.

- JOHNNY HUNKINS

Trick question: What's the difference between a sway bar and an antisway bar? Absolutely nothing. The linguistic shorthand of gearheads has abbreviated the more accurate term, antisway bar, in a way that mirrors the equally ambiguous role that this important suspension part plays in drag racing. (Note that in Motor Trend new-car speak, this part is referred to as an "anti-roll bar," which, though correct, may cause confusion to drag racers who know the part as an "antisway bar.") A rear antisway bar is the kind of part that is seldom pondered until you realize you need it, which is a good measure on which to base your need. We realized we needed one for our long-term 1968 Plymouth Valiant project car years ago, and we've put it off for too long. Nevertheless, we've some serious explaining to do before we dive in.

Mopars, which have a leaf-spring rear suspension, are probably the least likely cars to need an antisway bar for drag racing. They almost never need one-unless they've been converted (like ours) to a suspension type used mostly by GM and Ford called a triangulated four-link. This is the type of rear suspension used in the Ford Mustang from 1979 until 2004. It's also the same one used in GM intermediates (A-body and G-body) from 1964 to 1988, and in full-size GM B-bodies over their entire lifetime. Other rear suspension types, like the torque-arm suspension found in GM F-bodies (1982-2002) and the three-link found in 20052014 Mustangs, also benefit greatly from a rear antisway bar.

REAR ANTISWAY BARS: WHO NEEDS 'EM THE MOST?