As IO has mentioned, actually controlling an engine with the standard gash set of monitoring instruments is not particularily easy or accurate.
The fuel/air distribution is generally very poor in your standard Lycoming or Continental so even if you are using an EGT gauge for leaning purposes, you will only be checking one cylinder, the same with the CHT.
Proper engine monitoring and blue-printed engines are worth their weight in gold if you do long distances and have a machine worth spending the money on. For your average club hack. It isn't really worth it (unfortunately...)