I found a decent left side EAB head and the combustion chambers are a little larger - more volume when measured with fluid and deeper in the areas over the valves (measure near where the center would be; there is more clearance where the edge of the valve would strike) and the deepest part of the transfer area. It looks like taking an extra ~20 thousandths off of the left side head would even the combustion chamber volumes up but then they will likely need re-doming for somewhat uniform clearance to the piston tops.
untitled by
kenhenry_06268, on Flickr