My engine is trying to start but won't fire, and after a lot of trial and error I think my distributor might be installed "backwards" or 180* in the wrong direction. When I turn it, do I leave the spark plugs attached to the posts and turn the whole thing, or do I remove the plugs and reinstall them in the same relative place after turning the distributor?

 

Leave the wires in the place they are now. Hopefully, that's the factory orientation; #1 at the very front, slightly to the driver's side.

Take the cap off w wires intact, lift the dist body, rotate the shaft exactly 180°, drop back in, put the cap back on.

 

So I'm only rotating the bottom shaft. Thank you for clearing that up for me.