Here is a neat pic of Ray balancing a left side flywheel. HE balanced three sets over the last day. This makes a big difference in the smoothness of motors.
Here is a pic of a set of 55 wheels that my dad sorted out. he was able to get them within seven tenths of a thousandth of an inch. That is super precise. the indicators are test indicators and are accurate to half of a thousandth of an inch. The stock finger indicators are a joke.
Here is the 55 bottom end all buttoned up. The cam cover is installed so that we can check endplay on the cam. As soon as that is set, this motor will fall together. There is a ton of prep work to get this far, but it is a ton of fun.