In the exploded parts diagram for the 212cc version, it shows that the head is a tradition configuration divorced from the jug. Looking at your pictures, it seems like the head is integral to the jug, though. I was planning on polishing the chamber and surfacing to raise from 8.5:1 to 12-13:1 for methanol use, but if this head isn't conventional where chamber work is easily done, I need to look at something different than the 212-420cc Harbor Freights. How exactly is the head/jug arranged on it?