Thanks Trooper-san
I found the old link that brought up this question back in 2001 but it went unanswered. Your photos clearly show the gasket covering the 3 small passages on the exhaust side. Maybe they're supposed to be closed off but it sure bugs me.
I'm using a factory Isuzu gasket set this time (I think last time was Felpro). Block has been decked slightly so I'm planning to shave down the dowels/alignment pins a touch.
This has been a long strange repair starting from the classic coolant blowing out the radiator overflow. I never did see any cracks in the head and neither did the machine shop. Block was not re-bored, but cylinders were re-honed and new standard size pistons and rings installed. That was probably not necessary but the local shop ran with it before I could have any say in the matter. The new AMC head eliminates any guessing about cracks and should give the SpaceCab more happy miles.
Bob