Stroehlman - Here's some added info on your starter based on the "1107634" stamped part number. Not sure what the "YY" stands for as most date codes after the part number were 3 alpha-numeric digits. Perhaps the "YY" stands for a service replacement starter as the same number was assigned to both original starters and service replacements?
According to info in
GMPartswiki your starter was used on 1955-59 6 cylinder 12 volt equipped trucks for Series 3 - 6 as well as some similar GMC truck models of the same years.
It is in fact a 12 volt starter that would have been used with the 168 tooth flywheel ring gear, unless someone modified it to change the bendix drive for an earlier 139 tooth ring gear???
Below are screenshots from a
1969 Delco Remy Service Parts Catalog. The number "1107634" is identified as part of their "Cranking Motor - Group 53-H". If you look through the detailed listing of components, it shows your starter only has the 2 field coils as no "Coil - Shunt" part number is listed. Nothing odd about this, just the way it was designed/built. You can also see the specific component part numbers for starter service parts as they are directly related the the stamped starter part number.
Hope this may be of some help with yours and possibly other Bolters starter questions.
