Retros have smaller 18 inch wheels, a higher final drive ratio (3.9 compared with 4.6), a different frame and no leading link front wheel suspension. Engine, drive train and brakes are the same.
If you haven't done so already have a look at Soviet Steeds and Russian Iron forums. Lots of info and help on both
UralNorm screwed with this post 08-15-2012 at 12:47 AM