Only had one 383 in my life. It was mated to a 4 speed in a 69 barracuda formula S. It would nearly snap your head off coming off the line. Mine was a 330 hp 383 with a 10:1 CR, but many 383's in family cars were 270 hp with 9:1 or 9.2:1 CR. Not of the jump and run clan. Good engines, just not hi-perf out of the box. I really liked mine, but didn't hesitate a minute when offered a 426 hemi on a swap out. Just wish I would have kept it all, instead of throwing in the towel during the 1st Arab oil embargo.