Well...when you change your pants, do you put on clean underwear, or leave the old pair on? I change them, after all I have my pants off, so why not right?
All kidding aside, in my experience, I would have dropped in new p/c if your going through the whole block. They may measure fine, and be within wear limit....but 9 out of ten times they are near the end of that figure, and they get tired, rings lose their tension, lands get work hardened from all that mileage, and the ride will form at the top of the cyl. The cross hatch will be smoothed down, so the walls wont hold the oil as well and so on and so on. I have seen people re-use high mileage components...but to me its not worth it, theres not much life left in those parts. Besides, now the top end is fresh (Presumably) and if done properly is sealing tight, which means that you will get more oil consumption due to blow by past the tired ring package. It may run fine and be OK, but its probably going to use a little more oil at the very least. BTW RE-RINGING IS TO BE AVOIDED!!!