**600hp sbm block limit? Or is it bs!!**

They are advertised to handle that much shot, I believe the tune killed it.
I 'personally' would shy away from a stock cast crank @over 500hp...
but right on for making the power and living 4 passes.
I agree that a bad tune will make havoc on engines, that's why I took all precautions on my tune and took advice from some of the best nos guy's I no, I am confident that the tune was with in limits of a safe tune. KB Hypertech pistons are highly not recommended for any nos, in fact stock pistons would have lasted longer. All I wanted was the one weekend out of this eng and I was pulling it (crank and pistons had already bean ordered. ) My R3 I built makes 650+ Hp on engine only, got my 71 Valiant 4spd street --race car into the 9s Not sure I will even put the Nos on it.