Never overhaul an engine because of hours! If it performs well and doesn't burn a lot of oil, FLY IT!
As said before, a properly cared for Lycoming will easily go to 3,000 hrs. without a problem. My O-320 had over 2800 hrs when I rebuilt it and every part that I removed, more than met servicable tolerances. The only reason I rebuilt it was to increase the HP.