I'd check the valve guides for excessive wear, then re-seat the valves, and replace the guide seals if the guides are still within spec'*. Kinda late now, but check and see if there are any signs that the head gasket may have been leaking in the area around the problem cylinder, or in the area of the one clean burning cylinder. Kinda odd that only one cylinder was burning as it should. Maybe that one good cylinder had a minor vacuum, or coolant leak?
Also, make sure that the deck of the head, and the block are straight/flat, before putting the head back on.
Just a little friendly advice for future use. If possible, it'* always best to perform a compression test, before removing a cylinder head. The results of a compression test can say a lot about the condition of an engine.
Best of luck.