It does get rid of the sway, making it more driveable in the freeway. specially down narrow roads. i travel a lot to mexico and some of roads are very narrow with no shoulders. some of my first driving experiences where not fun. i had to slow way down whenever i saw a BIG F truck coming the other way. swaybar made a hell of a difference in stablility. This all with a stock 72 4x4 blazer, 31x10.5, with rancho 5k shocks.
Others have not noticed much of a difference, specially with stiffer suspensions.
anyhow, i put one in from a second gen blazer(77blazer). Go for the 1-1/4" swaybar if you are going to do it. you will need the front leafspring caps that hold the swaybar. as for the mounts that mount on the frame. I had to reverse the brackets(left on right, right on left). With a lift you may want to go with some disconnects, that's one of my next "future" projects.
you may also get some imput from:
Steve Chin(fabed his swaybar mounts) and
Burt4x4(had put in an aftermarket swaybar kit)
later,
ARQ.
1-72 4x4 CST Blazer
2-71 4x4 CST Blazer