If it's the smoke is blue, I'll wager credits to navy beans that the valve guides are on the loose side.
On fresh "race" engines "one" can run without valve seals. It is really the amount of clearance that the valves have that cause the oiling down situation.
The guides tend to rear thier "pretty heads" when you start a cold engine.
The rebuilder didn't say anything about knurling the guides did he?
Even the threaded in replacement guides seap a lot of oil because of the spiral grooves that are left.
The only good guide is a new one.
I hope that the answe is something small and stupid that everyone is overlooking.
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