Bob,

I'm not sure I have a specific answer to your question about coolant passages, but perhaps I can point you in the right direction and provide encouragement.

Several years ago I replaced the head on my Trooper (2.6), (casting #4), with a new AMC head. I got tired of replacing head gaskets. It's the best repair job I've ever done. I haven't had a gasket issue since.

I used a Felpro gasket, and had no problem. Of course, make sure you have it right-side up. That might make a difference. I don't recall seriously questioning the coolant passages. Maybe I just assumed that Felpro knew what they were doing.

I don't know whether they'll help you or not, but you might want to take a look at the pictures I've linked to in my sig block. You can readily see why I replaced the head.

Hope this helps a bit.