putting brake lines on my buddies 81 4x4 3/4 ton truck, broke the fitting off at the hose, then the fitting broke off inside the proportioning valve on both front lines. are the 1/2 and 3/4 ton the same? are the 2wd and 4wd the same? i don;t have my LMC book here to verify. i know the yard has a 3/4 2wd and a few 1/2 ton 2wd and 1 1/2 ton 4wd truck.