Well, the industry has come a long way since the wicked Witch from the West melting aluminum exhaust headers formed for the Swiss cheese Catalina's.
The aluminum now being used is of the T-356 type and can probably take more heat. I still would be nervous with them taking full open throttle bursts up and down the track. For the money, I'd rather opt for Titanium exhaust tubes that can take the heat and are most probably just as light because of the thinner gauge construction. For now, I'll stick with my thin steel headers.