Erick - better late than never!
78/79 sway bar mounts under the axle vs later models being over the axle. I wound up not taking it off between the time I installed and the time I took it off a few weeks ago when I upgraded my rear axle.
It did help quite a bit, but when I put it back on I also realized that my rear shackle bushings were no longer serviceable and had a tremendous amount of play in them. I upgraded to poly bushings and reinstalled the sway bar - this greatly improved control.
However, since I took the bar off as it won't fit on the new rear end, I have not noticed it being as bad as it was before. Could be that I am much more used to how the vehicle rides.
I think my bigger issue is shock valving. These soft deavers with extra weight of cage, big spare, big bumpers, 100lbs of dynamat, tools, etc really like to cycle up and down, so I think I need a lot more damping than the 255/70's I am running now.