First, so that you won't be chasing your tail, diagnose the problem. Here's how. Along every exposed section of steel line under the hood you can get to, clamp as many wooden clothespins on as you can get. This will allow the excess heat to go into the clothespins instead of the fuel. If the problem goes away after that, you know what it is.
Assuming you diagnose it as vapor lock (which is really rare, btw), here's what I'd do to fix it. Opinions vary, but this is mine. Since this is how I run a fuel system anyway, I would eliminate vapor lock to begin with. First, get a good quality electric pump. I like the Holley blue pump. Get it with the regulator.
Install the pump as close to the tank as possible. I like to get a 3/8" sending unit and replace all the line all the way to the carburetor with 3/8", but that's another arguement. 5/16" will be fine. Eliminate the mechanical pump. This will prevent the crankcase from filling with fuel should the mechanical pump diaphragm rupture.
Your plumbing should essentially like this:
You can see the regulator is used as the restrictor for the fuel return. This is the proper way to set up your fuel system. This assures a constant supply of clean, cool fuel to the carburetor. Except for cold starting, driveability will approcah fuel injected systems when set up in this fashion. Good luck.
