I have a pair of 273 Commando heads I scored off an engine with a broken block and crank I found abandoned in a junk yard. A four-speed at that! Anyways, how far can they be ported? What do y'all think the max cubes they can support is? I have the intake, too, but like an idiot, I sold the rockers a long time ago. I have no idea what casting number the heads are. These are deffinitely Commando parts - closed chambers, adjustable rockers, and an iron single plane intake.