Engine build number

Sidecar Flip

Living Legend
Jul 16, 2006
20150 Mc Carty Rd. Deerfield, Michigan 49238
I'm still trying to ascertain what or where the engine build number is. The only number referred to is the serial number on the right side case so if one assumes the engine build number is incorporated therein, it must be the last 6 numbers as the first numbers are the origin and model number? I'm wondering if that's correct (as far as the engine build number) is concerned. If it is, Bart and I have bikes that were built after the timing sprocket change. That will save a lot of grief here in Deerfield not that I can't take it apart, it's just I really don't want to.