Maybe start off with the correct numbers found on a Rupp 1971 HS40 55388C :thumbsup:
a 55355C will be a Rupp used engine but it is non lighted, its what the Enduro/blackwidow/hustler used. It will share the same longblock and carb/intake as the Roadster2 but since its not lighted the shroud, and flywheel/ignition is different.
the 55356c seems to spec out the same as the 88c (slanted/lighted) but may have been a different color, like say silver for a speedway or something like that :shrug: The carb numbers show different, but they are both bowl carbs.
a 55358C shows as a non lighted, standard length bushing crank, standard (not slanted mount) configuration.
I dont have any photos of a 1971, just of a nicely redone 1972 55388c that I had awhile back, but it had the Dell upgrade and bolt on header/straight pipe though: