That kit is for a half ton. I don't believe you want to do a lot of modification as parts for the big trucks are often hard to find even in the State's. You should be able to buy a new master cyl. real easily. There should be a booster under the frame. It's a big round thing with brake tubes & a vacuum hose going to it. The truck looks like about a 2 ton model. 50-60 series. It probably has 5 lugs on the front & 10 on the rear.
