I have used one on my 390 stocker for a long time.....because you don't have to watch the tach. usually have the chip set at 3400 and brake line pressure at 1000 to 1100 psi, put the throttle on the floor and let the brake pedal off on the last yellow, and redlight by .005 or have a .520-30 light.
Did break a cam bolt one time, and did notice some fretting on the crank sprocket. Bought a fluid damper and have not had any problems since.
you would be surprised what you can do with brake line pressure.......
