coil

I have a Subaru 2 cylinder EH720 engine. I'm putting 2 new ignition coils on it. I noticed the Stop Diode was not connected to the coils. Each coil has one spade terminal. THe stop diode has a single wire unused with a spade connector which looks like it reaches the nearest coil. My questions...

Any tips on setting a new coil in the 22hp Robin? If I recall from the manual the clearance is roughly .012 - .020. Is it as simple as setting a feeler gauge down on the flywheel and setting the coil on that and tightening down? Also, any tips on reinstalling the motor? What's the easiest...