What do you think could have been done to that ol' head? Always been curious about it.
It could have been milled quite a bit to reduce the volume of the combustion chamber. The intake valve-to-piston clearance can get pretty close on a milled head, and/or the milling takes away part of the valve seat area, so the intake valves have to be recessed back into the head after the milling job. Then the rocker arm stands need to be shimmed up the same distance the head was milled to get the right geometry back on the valve train, or shorter-than-standard pushrods have to be installed. Shimming the rocker stands is a better option. Sometimes a lash cap has to be added to the top of the exhaust valves to get them working right. Tinkering with a stovebolt head for racing can get into a LOT of work! We haven't even started talking about porting and polishing yet!
Jerry
