Are you talking about the 16" Budd type rims on the duals (6 hole rim)? If so they're locking ring, not split rim. The split rims are pretty hard to find anyone to mess with since they can come apart at any time and in some states they're illegal. The locking ring should be handled by any truck tire dealer. You're going to want to make sure that the groove on the rim is cleaned out (no rust) and the lip on the ring that goes into the groove fits snugly. The 17" drop center 6 hole rims from the later 1 tons will fit your hubs, but the 17" tires are tough to come by at least around here. I haven't found a 16" drop center that will fit the 6 hole hub. When you look for rims, there are two type of the Budd style-one for single applications, and one for duals. The single rims can't be used in a dual application as their offset is different. If you try to use these with duals, the sidewalls of the tires will touch instead of the rim centers. Mike