Actually, 32 lbs would theoretically be .032 seconds. But regardless of the formula between static weight and rotating weight, there are variables that can't be predicted. As noted, the "regular" DOT street tires will likely spin more. Then the shorter diameter may help accelerate the car, but it can also aggravate the potential to spin because it increases the gear multiplication off the line. There is also the slight variable that the added gear ratio may reduce converter flash just a little bit, which may or may not be a good thing and, last, but not least, there is a "margin of error" whether it be in how consistent your staging and shift points are as well as the weather from day to day (temperatures, humidity, barometer & strength/direction of breezes.
Ideally, you can see what the shorter tire is revving the engine to at the finish. That may help in determining the diameter of softer compound DOT/street legal drag radials you should consider. Then to help consistency, you can add weight (ballast - securely & legally) to the back of the car while you tinker with suspension tuning. (i.e.: spring clamps, shocks, pinion snubber, launch rpm's, etc.)
Track prep has been known to vary as well.
