I found a 69 C10. 3:08 6 lug rear on. CL for a good price. The rear had been installed in a 58 1/2 ton. 69 saddles had been cut off & leaf spring saddles welded on. I reversed that work & installed in my 66 C10. All C10 s have 12 bolt rears , pinion is slightly different than the car 12 bolts. I also retro fitted a posi unit. Truck has several hundred miles on it now & all seems to be working well. Seems to me you need to figure out the width you can live with & go from there
