More torque, lengthen the stroke. More power , increase the revs. So with a stock engine all you could hope for is a longer accelerator pedal to squeeze more hp out. As the piston crown reaches tdc and heads back down at 2000rpm it wants to leave the wrist pin behind. At 6000rpm the wrist pin is still trying to hang onto a cast piston, but the force has increased dramatically between going up, stopping and going back down...........the rest would be history.
It would be a good bet to see what would let go first, valve spring, valve, piston crown, rod, crank, bearing????????