What LB says, plus you can get an idea if an engine conforms by leaning in the cruise at say 65% or less. If it runs rough around peak EGT it is unlikely it conforms. If you can lean it past peak EGT and beyond until it looses power and there is no rough running, it likely is a conforming engine.
I reccomend the course, either online or with Jabba. For most pilots, there is heaps to learn.