Actually, once you figure it out and have the right tools, it makes perfect sense and is easy just a little time consuming.
I finished buttoning up the engine, gapped and installed the spark plugs (after doing this on a 911 I'd forgotten how easy it is when you have access), and stuck the distributor in (only open holes now are intake, exhaust, and oil in/out).
I was installing the 3B plug and ran into this:
Interesting that it was cast closed. Anyway, 5 minutes with a sharp hacksaw and I was good to go:
