As I've said before, you have the two-piece lock-ring rim. Far safer to work on than the split rim. I have mine worked on at a tire shop that handles truck tires. $5 to dismount, $5 to mount is what I pay. My problem was getting 15" tires that were big enough. I wanted some mud grips in a 7.00-15 radial, only ones we could find were made in Taiwan. Am switching my rear wheels to 16", have installed the hubcap clips, finished painting yesterday. Will get some 7.50-16's mounted after the paint has cured. I bought two rims from a 91 for $40. And the inner part of the rim where the hubcap sits is the same size as the older rim.
Problems with this change is the front wheels. The setback (distance from the back side of the rim to the mounting face) is deeper on the newer wheels. This will cause the tires to hit the tie rod ends. I calculated an 1-1/4" spacer is needed to clear, too long for safety without overloading your lug bolts on the front axle. So I will run my stock 15s on the front and 16s on the rear for now.
