David:
Aircraft wrenching is a great place to learn. You can't pull off the track or to the side of the road if your airplane engine fails. Your adventure has just begun. So, everything has to be right at the git go. But, like all things in life, things happen. As my Daddy said, "The most dangerous time to fly an airplane is right after an annual." I know. When I was cruising along fat, dumb and happy at about 2,000-ft agl, a jug blew off the engine.
Fortunately for me, the prettiest grass strip I ever saw was just ahead about 5 miles at 12o'clock.
For the very reasons mentioned and some that weren't--to make sure things are right--I devote one chapter to doing a preassembly just to make sure everything fits with the correct clearances.