Kip's truck is the lighter duty 6 lug. So that swap really wouldn't apply to you.
There are 4.10 center chunks out there for your rearend, though are more and more difficult to find.
If you're going to swap the whole axle, an 8 lug Dana 60 would be a good choice and are found in Chev/GMC, Ford and Dodge, which all have the same 8 lug pattern. Ring and pinion sets are also readily available. Dodge 3/4 and 1 ton vans usually have nice ratios like 3.54 and a lot have limited slip as well. They are usually about 65" wide at wms. A little wider than your stock axle, but can be made to work. Pre-1974 these axles are usually a bit narrower and closer to your stock width.
