I have a 53 3/4T PU and looked everywhere for replacement wheels for my truck. Give up, there are very few options. Here are the options I found.
(1) Find a complete set (all the same size) of the original rims and use them. Most tire shops will not work on these rims, however, coops in rural areas will because all the old farm trucks have them. The old rims work the best because of the tie rod knobs on the front come in such close contact with the tires. When using the old rims, make sure the tires you put on them are not wider then 6” to 6.5” or once again the tie rods become a factor. However, if you are planning to change the front end, none of this may matter.
(2) Now some will tell you that you can find 8 lug replacement rims off a variety of models from the 70s and 80s in salvage yards. And I did find some 8 lug rims available. However, they were too wide. I also called 1-800-USED RIM and 1-800-463 RIMS (Capitol Wheels) who both confirmed these rims will not work. I also called all the new rim manufacturers (well, maybe not all) including, Wheel Vintiques, American Racing, Cragar, etc. I found no one that made a replacement rim.
(3) You can send your rims to a company who will modify or custom the rim so they do not need tubes. For example, Stockton Wheels (http://www.stocktonwheel.com/) in California will do this for a fee depending on what you would like to do. I was quoted around $100 per rim.
If you find out anything different, I would be very interested. However, my old rims with new tires and the original hubcaps look pretty good.