Plugs are gapped the same all year I thought. 0.7mm or 0.025 in.
Do you have your timing light yet? Hook the clips to the battery, red to Pos and black to Neg. The larger clamp goes around on of the spark plug wires. The rubber plug above the dip stick area is removed so you can see the flywheel. Start engine, aim timing light at timing hole and pull the trigger. The light should flash. They are not bright enough to use with direct sunlight on the engine, you need to be in the shade at least. At idle there should be three lines in the window. Timing should be on the middle line I think, maybe it's the bottom line. Make note. Then raise throttle, engine speed, and watch the timing mark change, the ignition is advancing with rpm increase. The round dot and the F mark should be in the window around 2500 rpm, sometimes sooner or later. Note at what rpm it is at full advance. Note if it goes above full advance. Adjust so the dot stays in window at full advance. This is adjusting timing with a timing light at full advance and is a better way to do this than static timing.
Turn petcocks off, remove fuel hoses, allow all gas to run out of hoses, place cardboard under engine, go in house and watch TV for one hour. Then come outside and see if petcocks leaked.