Hot Fuel Lines
One, thing that I can add to this is that the cool carb plate under the carb appears to be made of metal. Get you one of those 1/2" thick insulating gaskets for the carburetor between that plate and the manifold and it should help keep your fuel bowls cooler. Also, wrap your header in the area of your fuel line. It won't look pretty, but it'll keep a lot of heat off the line. Maybe a temporary fix until you try rerouting things.