c30 rear end

[Rickey]

I have a 72 c30 dually and can someone tell what year models rear end will fit.

[Longhorn Man]

direct swap.... 67-72.
with some light fab work, anything will go. The 14 bolt is a very common swap and for many good reasons.
If you hust want to lower the RPMs, then just swap out the center section from any 3/4 ton or one ton with single rear wheels that had an automatic and a V8... the base model gear ratio with that eng/trans is a 4.10 (the tallest you can get in that diff) while you should have a 5.13... that was aautomaticly installed when the daul rear wheel option was made.
The diff drops out like a ford 9 inch, unbolt, remove from front, install a gasket or goop, and install the new. don't forget the new oil too.

[StingRay]

My 69 dually had a 14 bolt already swapped in when I got it. The PO told me it came out of a mid 70's 3/4 Ton. The 3/4 ton has the same width as the cab/chassis rear ends if you can't find a CC unit. You would then need the regular dually hubs drums and backing plates. I think the mounting flange for the backing plate has to be moved in too when using the single wheel rear end with dually hubs and brakes.


Check out the condition of your spring bushings, swing shackles, overload frame brackets, spring spacer blocks, ubolt saddles and the frame around the overload brackets. If your truck was used heavily and the overload pads are heavily worn it's likely that the top holes in the frame furthest away from the axle have cracks close to them. You have to remove the rivets and sandblast the area to see the condition. If cracked gouge it out with a grinder and weld from one side then do the same on the other and smooth it back out with the grinder. Reinstall the pads with grade 8 bolts, heavy washers on the back side and locking nuts. Sand blast all of the other parts and inspect for cracks. Weld or replace the spacers if cracked and replace the saddles if damaged. Replace the swing shackle and spring bushings if damaged.

If the overload pads are worn out they can be built up with weld (It's a lot of work) or a piece of heavy pipe can be used as donor material to replace the worn portion of the pad. They are not available new any more. When repairing the pads make shure to square them back up. The pad surface should be perpendicular to the frame.

Use new u bolts when install a new diff.