A833 Transmission leaking at reverse light switch

I got the new switch last night. I didn't drain all the fluid. The switch has an O-ring seal on it. I took out the old one and put the new one in quickly. Didn't lose much lube in the time it took to switch them. Maybe half a cup. I checked the fluid and it barely moved. It's just below the fill hole.

But,.... While working on cleaning things up and putting the inspection plate back on, my hand brushed against the passenger side header flange and it was wet. I just started seeing a little antifreeze puddle under the car, but didn't see anything leaking up front. From what I can tell, it is coming from the back outer corner of the head on the passenger side and dripping down onto the headers and running down.

Guess I need to dig into that now and figure out what is going on. It almost looks like it's coming off the header flange. Does anyone know if the exhaust bolts go into the water passage on 906 heads? I will post over on the exhaust section too. Maybe I have a loose header bolt and it is allowing it to seep out slowly.