Lean creates the heat. Its like on the new GT500's. If the exhaust starts running hot, instead of pulling timing, they dump extra fuel to cool things down. Trust me, its a lean condition caused by lack of fuel. What type of fuel delivery system do you have and what size injectors? It is possible that the car is pig rich at idle, which is why you are smelling fuel.
When you do a plug check at the drag strip, you never want to do it after driving back to the pits. At the end of the pass, you shut down and check the plugs, to get an accurate reading. The car may be pig rich at idle, so it would give you a false reading.