Hello Everyone, I have this nos distribution block pn C9TA-2B257-A , I would like to know what year and model truck this is for. I have a 1965 F600 that I would like to up grade to a dual circuit system. I would like to here from anyone that has done this and what master cylinder and booster to use. I would also like to do the same thing to my 65 F350. Any input would be greatly appreciated. btw It seems crazy that dual circuit systems were mandated on cars and lt trucks in 1967 but single systems were stil on medium duty trucks til well into the 70s. just sayin. Thanks Bill