John, Just curious, but why would you want to change out the head? If your original '54 235 head is good, I don't think the swap to an 848 head is going to net you much improvement over the existing one. Plus IIRC, you will have to deal with changes to the head/valve train oiling system which may be more of a headache than you want. Others with more experience and knowledge on the two heads and potential gains from a swap will surely chime in soon.
PS - Glad you cleared up the detail on the valve cover.
