The heat in Arizona lately plus the headers' heat and the usual underhood heat is very likely to have boiled the fuel into vapor. The alcohol in today's gas does that at a lower temp than real gas.
Insulating the fuel lines or shielding them will be the most effective. An aluminum shield that also keeps heat away from the starter would be a wise move. Check to see that your fuel lines along the frame are not too close to your exhaust pipes, too. Shields work there too.
The vented cap is very important if someone ditched the charcoal canister somewhere along the way. If you do still have the charcoal canister, check it to see if the filter in the bottom is clogged as a hint to the condition of other filters in the system. Make sure none of the lines to or from the canister (or the rest of the system for that matter) are swollen shut (will feel "spongy" on the outside) or bent too tightly so they are cutting off flow.
Check your oil for the smell of gas. If the gasket or seal between the fuel pump and interior of the block is torn that will be the result. The diaphragm inside can still go bad without that symptom. If you have to take the pump off, using a long bolt to hold the pump pushrod helps to keep it from getting too far away from the motor
Good luck, and don't think too much into it. Just check one thing after another analytically. There's nothing you can take off that you can't put back on again--with directions and the right gaskets or bearings of course.