on earlier models the "lip" was larger but over the years that was changed. The only difference between the models is that on a pre 94 TT you had an extra rib on the PS belt to take care of the extra load from hyrdo controlled HICAS.
Belt *lenghts* are the same for all years and models and pulleys from any year or model can be used interchangably on a NA electric HICAS (or removed) TT.
