Is Chrysler's current HEMI head on their 5.7L and 6.1L engine "really" different from that of today's other manufacturers' engines? I've looked at heads of several other engines, including Japanese and European origin, and their head (combustion chamber side) is more or less all hemispherical shape and the spark plug is at the center of each cylinder head. In fact, Chrysler's current design appears to be not a true hemispherical head engine; it has a polyspherical combustion chamber, but retains the Hemi's traditional inline perpendicular valves. I'm just wondering if Chrysler HEMI design has any special benefit only unique to them when comparing to other engines. Or is it just a advertisement gimmick these days?