I have been a machinist for years and its possible to make the adaptors, but to get them right without having one to measure by, is more trouble than it's worth. What I'm getting at is the American Force adaptors have an offset machined in them that keeps the wheels from sticking out to far when mounted on the truck. You would basically have to start with a straight adaptor and measure with a mounted wheel and tire. The wheels will stick out to far past the body if this offset isn't machined in the adaptor. It's really a lot of trouble unless you have your own lathe and mill. Also, the adaptors would have to be machined very true to keep from having a balance issue. Basically, the American Force adaptors are a proven setup. For most people, it's much easier to just buy the adaptors and have no worries.