Rear Sway Bars

I have one Barracuda with a front bar, and one with front & rear.

The slant six convertible has OEM soft springs and a Hellwig front sway bar. Yes, it does have some body roll, but it turns in sharply and points very predictably. I see no need for a rear bar considering its overall speed potential.

The Commando fastback has an Addco front bar with custom Heim joint end links (no bushings) and an Addco rear bar with poly bushings. It has OEM HD rear springs and big block torsion bars. Yes, it has much less body roll, but it also understeers if you can't get on the throttle (as is frequently the case on tight corners). It is however extremely stable at high speed. The tradeoff is it is much harsher on bad surfaces (the convertible is remarkably supple on the same).

You should probably consider how you are planning to drive, and what kind of roads you will encounter.