BB exhaust studs

Sounds like you have checked, cause you're suspicious too.
I have a couple sets of max heads, and both sets have the end bolts on both ends dry, but the rest are wet.
I would run a starting tap (the pointy kind) lightly into a second hole in, till it bottoms lightly, take it out and see if you get rust, or sealer on the tip.
You could also poke a stuff rod in, and see if it stops against something solid, or goes through into a water jacket.