Rakkka_firebird

Hello folks, Im just doing a little repare on my new old bike: Yamaha DT 125 MX from 1981. Im buying stuff from internet. What im not clear of, is if the models 125, 175 and 250 n also 80 or 50 from this same years are mostly the same or not ?=? (expect the motors) Thanks for your helping answers. Have a fiery ride. sunny greatings NicK