[markjohnson]

I doubt the 11.60's were through the mufflers but in the '60's NHRA required the car to at least have the original, stock exhaust still in place hanging in the Stock classes....but it was legal to have the headers open. That's why the infamous '65 Chyrsler A990 Super Stockers with 426 Race Hemis were built with a laughable lightweight, single exhaust system with a large transverse muffler at the the very rear of the car for weight bias. Seems crazy that perhaps the fastest musclecar of the Sixties, the '65 A990 Dodges and Plymouths, were built with single exhaust, but the car was constructed by Chrysler Corp. with meticulous attention to the NHRA Rulebook. Exhaust didn't have to be functional......just still in place.