even 300lbft is pushing your luck. Remember these engines are getting old now!
As said, it's torque not power that kills rods, so map accordingly.
I currently have a ko4 hybrid capable of 340bhp / 300lbft, but it's mapped very safely making 300bhp, with only about 260lbft, which it holds right across the rev range. Feels incredible to drive, and the power just keeps on coming and never stops, but it's low torque, and rod safe.
People have bent rods just at Revo st1 on ko4 cars....