1.6 rocker arms speed up the valve action and adds duration at the higher lifts. If the cam is too small for your engine then adding rocker arm ratio can add power. If the cam is already the correct size then adding rocker ratio will not add power, in fact, it might reduce power slightly due to extra friction. I did a bunch of rocker arm dyno testing for Hot Rod where we showed that changing the rocker arm ratio did nothing if the cam was already correct.