[Woodz428]

Aluminum isn't neccesarily weak, but since it isn't a stress part of the car it flexes probably more. It's the flexing that creates the weaknesses, except for the rock dings, that are likely in a hand hammered body. Aluminum has a lot lower fatigue cycle than ferrous metals, that's why the factory motorcycle race teams throw their frame away (actually probably back to the factory for analysis) after a certain # of races. I am not extremely familiar with the Kirkham body,but thought they were die stamped, which with the thicker material should make it more uniform and give more strength.