Just measured the hole centres on the top of the spindles of my spare '50 front axle. They're 3 1/8", and take a 7/16" bolt.
So you should be OK to fit the CPP steering arm on your truck. I would think that the rest of the CPP kit should pretty much fit too, we've mocked up the same P/S Saginaw installation that I have onto my elder brother's '36 low cab 1/2 ton truck, it only needs a few alterations to the steering box mounting bracket to fit straight on to the '36 chassis.
Stuart.
