So after opening up roughly 50 different gas tank threads, I finally found a picture of these on someone elses build. It appears they are spacers that go between the frame and the tank to keep it from hitting the underside of the body. Does anyone know if they are supposed to be bolted on or just clamped in place by the straps? Seems odd to have the holes in the bracket and gas tank flange without bolts! Picture from another thread shows some that appear to be bolted in.