No, it is not a B20 head, i measured the valve sizes and they are the correct B18 smaller sizes. Also my casting numbers are not under the valve cover. looking at the valves though i noticed the "dimples" on the face of them are rather on the large side of what i have seen on most valves. Is it possible that at sometime valves with extra large face depressions were made? This engine had some very odd Melling lifters with NO oiling holes so some odd valves would not shock me. I think i will order my new valves and re-measure at this point. I am all out of other ideas.