If you're happy with how the car sits and the bars are in good condition, then you can re-use the bars.
BUT. Your car will handle about 1 zillion times better if you buy a larger diameter set of torsion bars. :D
I understand they aren't always in the budget, but Ma Mopar really did do all of us a big disservice when she decided on the spring rates for the torsion bars. All of the musclecar era mopars are undersprung from the factory, even the /6 cars. A set of 1" bars from Just Suspension (less than $200!!!) will make your car handle MUCH better than it does now, with a ride that is still a long way from stiff. Even on a /6 car.
I have a set in my Duster. Stock lame shocks, 225/60/15's, no sway bars, and a 318. Still VERY compliant, but a lot less body roll than with the /6 and /6 bars, and much more predictable handling. I'll probably end up going 1.06" for torsion bars later down the road.
PST (site sponsor) also sells 1.03" bars for around $200. Money well spent in either case IMHO, even for a plain old /6 street driven car. They may be old cars, but they can be made to handle MUCH better with a few simple improvements.
