The fuel issue, like yours, has been an ongoing discussion on the FBBO site. One guy tested the current pump swill and found that the fuel boils at 150*. Think about that. Your engine is running, on the coolant, at 180* or more. Mix in the radiated exhaust heat plus other heat sources. On my own 65 Coronet, after driving it for 20 minutes or more, would have the fuel boiling in the tank. Car has 3" TTI exhaust that at that area has anywhere from 1" to a little more for clearance between the pipes and the tank. The car would be fun to drive since it was blubbering from fuel boiling in the carb too. I put on a carb heat shield plus used the blocked off heat riser intake pan shield/gasket and that helped on the engine side but the other end was still an issue. For sure we need better venting back there. Is your fill cap vented or non vented? Mine was vented but I still got a whoosh when it got opened.