footbrake racers
I have a 68 Barracuda street car and have been searching for 60 ft time gains too (mine are more with gaining wheel speed through tuning right now). I've raced fully stalled against the brakes (3500 rpm), flashing it off idle and currently leaving in between (1800-2000).
My best 60 foot times in the past have been flashed off of idle. My car (stock suspension no add ons, MT Indy Profile SS tires) reacts best to this, but my lights vary more. I also found that my car picked up some 60 foot (years back) when I removed the tall adjustable pinion snubber and went back to the stock stub when leaving off idle.