On the parts list (effective Nov. 1 1967) #214 rear wheel spacer 3/16" -from sprocket side to frame (bearing in sprocket)
#213 Front and rear wheel spacer 1 15/16" -from bearing/hub side to frame
They did not use inner spacers, or even an inner bearing on the sprocket side wheel halve, they actually used a flanged bushing on that side (kinda like what a riding mower has) just to take up the space more than anything for people that actually greased the wheels with the zerk fitting. My 1968 model 600 wheelset is like that.