There were several iterations of the AC condenser fan shroud assembly, but they all used the same fan. The problem seems not to be the amount of air sucked in & through the condenser, but the velocity of the car while its happening. The system depends on air sweeping over the top, curling down to the pavement and back to the bumper, where the fan sucks the air in, blows it against the rear tub so it folds down below the incoming air-swirl. This works fine at around-town speeds. But at high speeds, that swirl is well behind the car, so the fan is trying to suck air from a partial vacuum. Head temperature goes up, pressure increases and eventually a hose blows. Wings & slats confuse the air flow issue even more. What is needed is a true airflow study done on the car at varying air speeds to confirm or modify this idea. We're all guessing here.