I believe anything over the 904 piston size would be a little risky until theres more feedback on them on the road as far as longevity goes.Larger pistons means more weight,heat,and bigger clearences of the piston and rings which means more piston slap and oil burning until it warms to operatin temp.When i installed my 904 i thought the pistons were the wrong size because of the needed clearences of an air cooled motor.Just my 2 cents worth
