Yup....that's what it was. I spent an hour burping it with a funnel when I put it back together. My mechanic buddy brought home a tool that hooked to the rad cap and a compressor and it sucked the air straight out of it! Had to add nearly a gallon of coolant back to it.
So other than a small oil leak fromt he rear main seal....I'm good!
Now if only I can find some time to actually clean it up for the cruise-in! If not, I'll be cruising dirty and proud! :D