Depends on what you mean by rebuild. Most of the low mileage cars need what I call gasket freshing. Basically, the motor suffers from leaks (rear seal, intake, etc.) . This really is not a engine rebuild. If you bore, hone or balance it then its a rebuild. In general, I tell people if you tear it down do to a rear seal, its worth the time and money to put a cam and chain in it. No better time.
Robert