this is the modern "hemi". note how high the camshaft is in the block, and notice the nearly-horizontal pushrods and shaft-mounted rocker-arms. deepskirt block keeps it stiff, aluminum makes it light.
the legend. note that the heads themselves are not as large as the valve covers! nothing but business going on under those....
...and this was the business. shaft-mounted rocker arms on the classic. it was noisy and consumed a lot of oil. pretty ruckus for the street, but just what the dr. ordered for the 1/4 mile.
now THESE are hemi-spherical heads. just like the name implies. you could eat your soup out of these bowls. these are aftermarket aluminum versions, but the shape is all hemi.