I was changing the valve cover gaskets on my '70 GS 350 and noticed a small amount of coolant (antifreeze) inside at the bottom of the head. I borrowed a coolant light tester and found a very very small amount in the crankcase. This engine has only 55K original miles and is super clean inside. There was no milky substance anywhere. It runs perfect, does not smoke or any steam whatsoever. This car is not driven very often. What do you guys think?