come on dude, the back brakes are bigger because when its loaded, thats where the weight needs to be to stop it, if its empty the front is heavier and only needs the back to "Line up" the braking direction. If it doesn't the truck will spin out (swap ends)of control. As for tires, look for used, junk yards, craigslist excetra. or swap to newer with discs. I just pulled a ho72 514 out of a 67 one ton, going back with a gm corp 14 for gearing reasons and discs
