1973 318 - daily driver for years - now won’t start

i originally thought jumping timing chains was a joke until it happened to me. I parked my '69 Dodge truck (318), went to leave later and she would crank but not start...every once in a while a small puff would come up through the carb and realized it was no joke . Got it towed home(by a damned Chevy of all things) and found broken tips of the gear teeth and slipped time.