Ok, a few months back I was having a overheating problem. I and a couple of friends agree I have a blown head gasket. No water in oil though. I took the heads off look the head gaskets over and I couldn't see where they had failed. I cleaned the heads up, reseated the valves and replaced the valve seals. After I clean the heads, I reinstalled them with new head bolts. Then I reinstalled the Intake and was getting ready to put the hoses back on. That is a blue paper shop towel. I looked back a my pictures. The last time I had towels around the open engine was when I had installed the aluminum intake close to a year ago. That's my story and I'm sticking to it.
A friend was rather *backside* in his ways about keeping things covered while apart. Finished the freshening and fired it up late at night. Ran funny. Came in the next day and looked around carefully before diving in. Blue shop towel threads out behind the exhaust. Pulled the carb and there was no sign of the rag that he must have left in there. Ran fine after.