LA small block timing is suddenly way off

MSD shoots up to 6 sparks at low RPM and gets down to one fat one above abput 3000. If your timing light sees 6, just use the first one. Edels dont have power valves, a backfire wont do damage 99% of time. Pulling the timing cover may be well within your future, even to check on your chain make-up. Replace the nylon if you got it. timing chains are inexpensive. while you are down there, buy a Mopar tensioner, best thing you can do short of a gear/cogged belt drive for timing consistancy. 30 crank/15 DISTRIBUTOR timing off is bad but it wont disable the car. you should be able to adjust it out by turning the dizzy. 15 CAM timing is bad. that is your chain.