Slant 6 Aluminum Performance Head

kinda hard to CNC water jackets..gun drill? Id propose a 2 piece head with a top and a thick bottom. Top would just be to cap off the routed water jackets, no cylinder pressure. Wasnt there an AMC drag racer that would top a head and graft another on top so he could get a taller intake runner? "Hey, they are factory heads!" :)