Remember that we haven't proved that the problem was due to valve leakage. Leakage fit the symptoms, especially in view of the very small tappet clearance, but the proof of the pudding is in the eating. The next step is to put it together and see how it behaves.
Remember to use a decent gasket on the valve chest cover/PCV valve. I re-use old ones if they are in good condition, but Briggs does not approve of my miserliness. However a slight leak in that gasket will only cause oil leakage, no other change in the engine's behaviour.
