Sorry for the delayed response, I haven't been on the site in a while. The cab and bed are from AMT's C-3500 phantom dually kit. I had lowered the original kit and made bigger rear tubs to fit the tires.
I ordered quite a few parts this Spring prior to seeing the 2015 health issue posts. I received all of my parts I believe within 4-5 weeks. Maybe they received so many orders they are trying to catch up similar to the Modelhaus?
I had one of those MPC 4x4 Dodge kits. The tires were 1/20th scale street tires. The Dessert Dog Offroad tires on the Fall Guy pick up will fit on these rims. My only worry about sleeving them would be the centers would be too large. Craig