Mike,
With your car having the ladder bars, the rear end already acts as the anti-roll bar. If you are having excessive body roll, then be looking for broken brackets, twisting axle tubes, or other places that can be giving. The other extreme would be if the ladder bars were mounted real close together, but when I looked at pictures of your frame that doesn't appear to be the issue.
Usually with cars that have the real bad twist, adding the anti-roll bar will usually slow down the 60ft time. The reason is that it will pick both wheels up evenly and therefore starting the clocks sooner than having the passenger side wheel stay on the ground and roll through the beams.
Could the front wheels be in the air at the 60ft timers? If your 60ft numbers are slow, then your 1/8th mile and 1/4 mile MPH will be high for the ET. Just for reference, my car with 1.23 60ft times will run 5.64 @ 121 in the 1/8th and has been 8.90 @ 152 in the 1/4 with the 1.80 powerglide, 4.56 gears, and 16x33 slicks.
You can input numbers into this equation from Wallace Racing and it is pretty good at showing the estimated times and MPH.
http://www.wallaceracing.com/etcalc.php
Later,
Bill