We've all been zeroing in on the valve guides, which Jim reckons are fine (I think).
What about giving the whole engine compartment a good clean-up (degrease it), and then observe the engine block and seals/gaskets for any minor/microbe leak? Sometime it could be a very fine leak - so much so that whatever excess of it burns up with the engine heat.
A probability if we assumed the valve guides are fine?
126 tailed by a 203, 129 leading the pack.