1978 Dodge 440: Gas has funny smell, Backfiring, etc

I think Scott may have it correct. If it will start when it cools off, more than likely, the timing chain is stretched, and needs to be replaced as a full set. I recommend a double roller chain set, with gears. GMs are also guilty of this problem. If the ignition box goes bad, it usually just dies and will not start. There is a test procedure for the boxes, but I do not remember it off the top of my head. A good "Motors Manual" will have this information, and others for trouble shooting.