I think my 727 is fried. Now I'm at a crossroads...

I could be wrong but it looks like the power brake line goes to #8? I do lose fluid, but I've always attributed that to my leaky proportioning valve. I pulled the plugs and they are all rich. I do remember richening the mixture when trying to see if that would solve what I thought was a lean condition. Didn't work.

Here's the #6 header, you can see how it's dull and some of the finish became powdery.