21. After eleven pulls worth of adjustments and tweaks to the computer program, we were rewarded with the best pull of the day. The peak power of 720 hp at 6,300 rpm and 662 lb-ft at 5,300 rpm should be more than enough to propel our ’68 around the track. We were especially happy with how the 461ci small-block LS made over 400 lb-ft of twist way down at 2,500 rpm and by 4,000 rpm was churning out over 600 pounds. Even though peak power was at 6,300 rpm, we were getting just over 700 hp at 6,700 rpm with no hints of valve float.