I'm guessing this is the first motor you've ever taken apart.
Well, since you pulled it down, just start piling up your pennies to rebuild it. No need to go mic'n the bore. Just go find a shop and have them bore it. No sense in going that far and not doing it right. The shop will tell you how much it needs bored. No need to measure it.
No, before you ask, honing it and slapping a set of rings in it isn't a rebuild, and it's a waste of time. Do it right, the K series are cheap motors to rebuild. Done right they last, oh, around 25-40 years depending on they're use. (About 1500-2000hrs or more if you take care of them)
