First Cross Country - Hot Cockpit Normal? Gas Overflow at Header Tank?

Yes, the cockpit is warm on a 80 degree day, I always fly with the canopy open partially and even with new cork gasket my header tank leaks a small amount of avgas onto the windshield. Just add, wipe off windshiled to pretake off check list. I'll put up with it just knowing I have about an hour of gas in that header tank. Happy flying with your new ride.

Rustypilot

My cabin air knob should be labeled cabin heat as well. I fly 7567C. A 1959 Forney Aircoupe Execta. It’s warm in the summer in Houston, and even more so in the cockpit.

I would look at repairing the hot air valve first, then the insulation on the inside of the firewall, you are not allowed to put anything on the outside(engine side) of the firewall.

I do have an air hose that runs from a firewall flapper valve to an air intake inside the starboard engine cooling opening.  The cabin heat seems to be set up fine as well.
There is very little insulation on the firewall and the fiber that seems to be there seems to be 75 years old.  With the exhaust pipes being just few inches in front of the firewall it would make sense that they would heat up the firewall.  Should I replace the firewall insulation on the cabin side, or purchase a more modern fiberglass insulation/fire block that would be installed on the exterior of the firewall?  What about exhaust shielding or fiber exhaust wrap?   Or, do I just enjoy having a toasty cabin for flying in Washington state?

Brady, As Matt points out your engine receives its fuel from the header tank. In my opinion it is a good operating procedure to consider that the fuel in your header tank, approximately 6 gallons, is your reserve. If possible you should not deplete it. Always keep plenty of fuel in the mains. Congratulations!

Your coupe feeds the engine from the header tank, there is no keeping it as a reserve. Both mains are interconnected and feed the fuel pump, it fills the header, any extra fuel returns to the mains by a return line from the header. The engine is fed by gravity from the header.