Don't worry about it unless there appears to be deep pits. Minor surface rust will polish itself away with a few minutes' running time. Look at a disc brake rotor after just a few days of non-use. The cam lobes are constantly bathed in splash oil from the crankshaft and rods, so slight surface rust will disappear even faster than a brake self-polishes.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!