Originally posted by LONGBOX55:
Any 1 ton rear end is going to big, and I would not suggest going with smaller brakes. Try finding a 3rd member from a '67-'72 3/4 ton, they are intrchangeble with your current rear and I have seen them with 3.55 gears. This would be easier than swapping rears. If you do want to change the entire unit then get a 14 bolt full floating rear from a '73-'87 c/k 30. If you want to do a 4x4 swap get the Dana 60 from a k 30 as well.
I'm fairly certain that the only stock gearings in a '67-'72
3/4 Ton were 3.90:1, 4.10:1, and 4.55:1. It is possible that I am mistaken, but I am fairly sure that I am not.
I believe that the Half ton had a 3.55:1 ratio available, though. If you had the whole axle, you might be in business. IIRC, by that time they'd done away with the torque tube setup, so it may be as easy as bolting the thing in.
Just remember: Smaller Brakes equals Less Stopping power and that truck weighs a little bit more than I think you think it does.
The stopping power of your brakes won't change, but the amount of force needed to stop your truck will, as you accelerate. If you're doing 70, and you've changed your brakes to a smaller model, then you
WILL have problems stopping when you really need to. And that really isn't a good time.
If you do reduce your brake hardware size, be sure to pack an extra pair of underpants behind the seat.
You'll need them sooner or later.
