I subscribe to Muscle Car magazine and they publish specs on almost all the cars they review. Unfortunately, most of the quarter mile times and trap speeds are from magazine reviews in the 60s when the cars were new and they were all running bias ply tires. Many of the muscle cars in those days ran high 14s and low 15s in the quarter with speeds in the high 80s and low 90s. The cover car in this month's issue is a '66 Chevelle Malibu SS 396 360hp with the good old Muncie M21 close ratio 4 speed and 3.31 gears. The magazine times from back in the day said 15.50 @ 89 mph. That just blew me away since my 302 Mustang with very minor modifications, a C4 with shift kit and 3.55 gears has posted a best of 14.308 @ 99.1 mph. How much of a difference do you think bias ply tires made?