In the mid 70s, I had a Dana 60 in my 55 Cameo 1/2 ton. The rear end was from a 3/4 ton with leaf springs and the pads only required a minor amount of modifying to work with my original springs.
The wheels did stick out a little, but I was running 10 inch white spokes. I don't remember what universal I used to solve the problem, but the yoke is larger on the Dana 60 and I was able to find a universal at the parts store that matched the bigger yoke on the rear end to the smaller yoke on the driveshaft. It took a little measuring and searching, but the part was available.
The other alternative, is to cut off the yoke from the driveshaft and weld on a 3/4 ton unit. I have done this with other rear end swaps, and it is much more expensive than using the universal to match the driveshaft to the rear end.
I am now running a 76 Blazer rear end in the truck, but will be converting back to the original rear end. This rear end is wider as well, but fit under the truck with only minor modifications.
Bob


55 Cameo 396 TH 400 with overdrive
65 Caliente conv
67 BB Caliente conv
67 Mercury 1 Ton
76 GMC 3/4 ton 454ci
84 Buick Turbo Regal