Classic/Antique Car Repair: 57 Thunderbird - vapor lock, Vapor lock

Question
57 Bird owned since 1963. Know it well.  Seems to have developed "vapor lock" issue.  Once hot it "runs out of gas" on interstate at about 72mph.  And will continue to gasp and sputter until throttle back and then recovers about 60mph.  (I'm in Florida and on a hot day when the car has been run, the problem will present at around 45 mph under hard acceleration from a traffic light,) Holley 4barrel has been professionally reconditioned.  Have already replaced with new: gas tank, gas lines from tank to fuel pump, fuel pump, flex line from fuel pump, gas line to carb, vaccum advance, gas cap. I'm running out of ideas and still have problem.

Answer
Modern oxygenated fuel is causing this problem in many old cars.  Modern cars have a recirculating fuel system which keeps a surplus of fuel going through all the lines, the excess is returned to the tank - resulting in cooler fuel lines.  Old cars have no such system - the only cure is to add a booster fuel pump in series with the factory pump - the best location for this is back near the tank - but situated such that it is protected by the chassis from road debris. Mount the pump as low as you can safely install it, hopefully where it can gravity feed from the tank.

Wire the booster pump so that it goes off with the key, and also through a toggle switch you can install where you can operate it from the driver's seat.  You will need to turn it on only under the conditions you describe - hot weather, high speeds (or after the car has sat in the hot sun long enough to boil the fuel).

Dick