Dan, I have tested it in the same day last year. With the Proline kit in.... I ran it with the 24 and the 23 on a 3000 ft road and the 23 out pulled on top end by 3mph and out accelerated the 24 top gear from bottom to top and that is with NO machining done. There is a reason why most Attacks are faster than most Apex's. A guy on here last year had Proline kits in two Apex's and two Attacks. For some reason he had 4 sleds. The Attacks were faster on ice. He said the attack always ran 121-122 and he could not break any faster than 119 on both Apex's. You may see it if you had a long enough run, like 1-2 miles, but I know the gear is everything, clutches machined or not. That's why 90 percent of the performance people are telling everyone to drop to a 23 or even selling the gear with the kit. The 23 works.