A-body chassis dynamics, handling

I was wondering about some general handling topics in relation to our beloved A-bodies. Now I almost always see guys building road-race Barracudas (64-69), with one exception being the Mopar Action "Green Brick" '70 Valiant. Is there a particular reason for this? Also, it seems like Dusters have a rear overhang quite a bit bigger than the other A-body models that would have a negative effect on handling; is there any truth to this?

On a more detailed note, how do shock-absorbers affect handling? I believe the shocks in my Duster are shot as it would sway and wobble like a b!tch going over bumps (sometimes almost out of control if turning at the same time), and I could get the whole car into a wobble motion just by pressing down on the fender a bunch of times. Also, how noticeable of a difference should a front sway bar make in handling? I noticed a very slight difference after putting my bar in but I'm pretty sure that was just because I was running up against the bump-stops when going around corners at speed and the bar wasn't mounted very well (endlinks pointing out and forwards, and center mounts able to flex).

Sorry for all the questions, but they have been bouncing around in my head for weeks and I want to learn more about suspension tuning.