Stroker engine "diesels" after I shut it down

Timing using the total method is not the best method for a street driven car.

If that has the 292 nostalgia cam in it, it's gonna need every bit of 15-18 initial. My 2 cents, get the car warm and turn the initial up to 18*, reset idle speed and shut it off. Try to restart it. If it doesn't kick back, see if it shuts down without run on.

Reducing total timing will most likely make the problem worse. Your issue IS NOT a total timing issue, it's an initial timing issue. It will probably take some tweaking of the distributor advance to get it straightened out.