AD Eng $/& is quite clear, operating a private aircraft on condition is relatively straight forward, main consideration is good record keeping, oil consumption, temp and pressure trends.
There is a very good article on TBO in the latest EAA magazine that debunks all the commonly held shibboleths.
Proerly Cared for most IO 360 in C172 will go well over TBO very reliably.
The ancillaries, oil lines and magneto drives are more of a worry than the core of the engine.