Im pretty sure the master cyclinder on my 70 is original. I figured out that to order the same exact one I have to get a 69. I've looked at quite a few engine pictures and all but one had the 70 unit. Im guessing that both were used on 70s. Does anyone know if that is the case? I think I will use the 70 model if they are interchangeable since it has the original color finish on the cover and its cheaper. Thanks.