[bret a ewing]

David,

Please re-read my post, "street tires" were specified. Traction concerns......well, in a lightweight car like the cobra, hooking all that torque to the pavement is another matter, as most of us know.
Launching from a stop, or a badly mismatched-rev/gear downshift will produce tire slippage.

I guess if the driving duty example (of the cobra) was a lot of high rpm, to immediate hard downshifting, the failure rate would be higher. But I believe that type of driving is the exception rather than the rule.
Mind you anything is possible and I'm sure folks have examples of every type of scenario. But for 99% of street driving a cast crank will hold up just fine. KC puts them in his 600+hp crate motors with excellent results.

Morg,
I talked to the engineering dept at Scat. According to them, their cast crank will handle 600#s tq +.