An IO360 200hp injected engine has a 2000 hour TBO the 12 years is only a recomendation.
Have heard of 360s running for 30 years but a bit over the top.
Lycoming do say it needs to be run 40 hours a month to make this TBO.
Pre 72 engines had narrow cam widths and only had a 1400 hour TBO.
Valve guides wear and a need wobbe test every 400 hours, unless you have the new hardened guides, good for over 2000hours.
Once passed TBO it's on condition, have heard of engines run up to 2800 hours.
Cam lobe wear is common, only indication is a slow reduction in power over time.
Old CAA C/A climb test is good to catch this.
Creeps up on you when the trees at the end of the strip seem to get taller.