Almost looks like red lithium based chassis grease. Hi-Temp Valvoline Moly wheel bearing grease might be okay, but that may be a little iffy. I see enough going on that I would at the least pull the rockers and check the valve stem heights and check the puchrod legnths. What you find there is going to give you an idea of how much farther you need to look. Probably also be interesting to see what's behind the timing cover, being that's only about $12 worth of gaskets.