It seems endless but I'm getting there. I didn't realize the barrels were so jammed into the cases like they were. The other barrels weren't so bad. Wish I'd known when I installed the 903 crank.
Much better tool. The brick wall I felt was the valve seat cast into the head. Good place to stop. I have a plan on how to resurface the plug land so the gasket will seal against the head. More to come.