The flying club I do a bit of part time teaching at has Transport Canada authority to run their Lycoming O 320 D2J engines (2000 hr TBO) to 3500 hours.
The last 2 engines made it to 3500 hours with no problems and were exchanged for Lycoming factory overhauled units.
The club got full core value for both so the extra 1500 hours was free time
Frequent use with good operating SOP's and good maintenance will allow most engines to easily exceed the manufacturers TBO.
It is low use and bad operating practices that kill engines, not hours since overhaul.