Ok. so if the spark is weak in 2 cylinders that means the coil is ok. the points are ok. There may be a problem with the cap on the distributor, the wire or the plug. See if the problem follows the plug and wire by swapping them with Cyl #3. If they do you might want to check the plugs and wires individualy.

Now for the sync you need to listen for the difference in sound. Adjustment is done by the 10mm linkage. Like Tom said, that's last.

Stalling in gear is usualy a vacuum leak. Take a fire exstinguisher and some carb cleaner and spray around the manifolds, carburator base, the 2 vacuum lines from the carbs and there should also bee a vacuum line for the brake booster and one that runs from the manifold around the engine bay and is used for AC or auto door locks and such. I would just plug the AC/door for testing purposes.

What color are your plugs? black to rich. white too lean brown just right ...