What's a good candidate for swapping the complete rear end out of a '62 dually? My truck has the split rims and I believe 5.14's but I'd like to go with a little less gear such as 4.56's and one piece rims. The local pick and pull had the remains of a '75-ish Chevy dually with the rear end still in place, pretty sure it was a column shift AT. What gear would be typical for that truck and is that rear a doable swap?