All the Engineers had to do was to plot the 1.50 ratio dots on paper and then make the rocker tip follow that arc. Something the stamped ones cant do with their pockets, and the HD stamped rockers with their thicker cross sectional area at the pocket has been busted as a myth. I think Isky still has these rockers in their catalog. IIRC the 273 rockers were cast iron and the 340 mechanical rockers were forged. Any 2nds on that?