Below is information I have gathered online regarding Piston Engine Aircrafts:
2000 Hours is usually the time for a piston aircraft engine before needing to be overhauled.
When looking at used aircraft, there are usually SFOH (hrs since Factory Overhaul) and SMOH (hrs since Major Overhaul). The main difference is that the SFOH refers to a manufacturer overhaul vs the major overhaul which was most likely done locally or independent facility.
Factory overhauls are generally more expensive.