Just a thought,, on a trip across the country with my 67 Dart I was smelling gas while driving. When I would stop, open the hood, nothing.no smell everything dry. I would check it when hot, cold still nothing.What was happening was as rpms were up while driving the fuel pump was leaking. By the time I'd stop the engine heat and shutdown the gas would evaporate.Drove me nuts for 2400 miles.Should have known because the fuel milage was off. Just last week it happened to my truck(318) but I caught this one.After start up I got stuff out of the bed and when walking back to the truck I noticed a few drips so I opened the hood and sure enough the pump was wet.My shop is 3 miles away so when I got there,poped the hood and it was dry as a old bone.One was on the shelf so on it went.Again just a thought