A unique feature with the shaft mounted rocker arms such as those found on the Y-Block (as well as the FE, MEL, and LYB) Ford engines is that the solid lifter or lash adjusting versions can be measurably variable in the rocker arm ratio depending upon where the lash adjusting screw is positioned within its range of travel. Continue reading “Altering Rocker Arm Ratio By Varying The Length Of The Pushrods”