Keep in mind that the chain roller wears deeper into the tooth valley as well as the front side of the tooth. When you turn them the chain will still run low in the valley and ride hard on the stripper plates. If there is any slop between the sprocket and the shaft, when you turn the sprockets, they will wear even faster on the shaft. If you think about it, the feederhouse chain and related components are the more important service aspect of the machine. If it fails and the chain gets into the rotor, you will be paying a lot more money for that repair than an entire feederhouse rebuild. I would take a closer look at the condition of the rest of the feederhouse components before making up your mind on the sprockets if I were you. Once you have the thing that far apart, it would'nt take much more time to complete the job.