I had a 30ft 86 HR Alumilite, we had many wonderful trips in it. One thing I recall was that it was prone to vapor lock. Vapor lock is when the fuel gets so hot that it boils. The fuel pump and carb doesn't know what to do with vapors. There were some modifications to help with the issue.
#1 was a sheet of aluminum that guided air to move past the pass exhaust manifold.
This was to get rid of the heat near the fuel pump etc.
#2 was to move the fuel line to the outside of the frame rail, away from the exhaust.
#3 was to install a fuel pump at or inside the tank, fuel under pressure is not as
prone to boil or vaporize.