I'm with Neal on this one. The problem is that the turbo cranks had the rolled fillets to improve FATIGUE life, not to add more strength. So the na cranks will handle just as much power as the turbo crank, but for less time- fewer cycles. And since the fatigue is cumulative, there's no way to know how much has been "used up" over the years. The rolled fillets should survive 20/20, and maybe 30/30, but there's no way to know for sure, unless some of the fillet is still visible after the crank has been turned.