[GrouchyOle'Man]

UPDATE Still fighting a miss on the engine. Checking into a valve gap issue as well. Will close up the gaps and keep informed. Any other ideas (besides a badly worn chain) let me know.
Closing up the valve clearances produced no difference. A badly worn timing chain can negatively affect timing. The backfire I am getting could be due to a retarded spark I presume and that is definitely a possibility on this engine.