To tell where the convertor hits/ flashes at, I put the car in high gear, and at a slow roll stab the pedal hard, watch the tach.

69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam, footbrake street/strip car
Best so far, 10.32 1/4
1.41 best 60 foot
6.56 at 104.17