have you ever seen this before

No way is coolant getting in there. There's no coolant very close to the #2 intake port. 2"-3" away. The Pontiac intake is set up same as a small block mopar... there is a coolant crossover area at the front of the manifold, but it's in no way close enough to the intake ports to have coolant leak in. And that wouldn't explain the #7 port at all. No coolant anywhere close to it, the passageway in the head is blocked and not even under the manifold.

I guess its too late to check, but were the #2 and #7 ports in the intake clean & shiny too?