We just recently built a new wagon bed using 4 x 6 sills and 4 x 4 cross beams then topped off with 5/4 x 6 boards onto an old John Deere running gear. The wagon can be used for bales and the grandchildren can decorate it for parades. As we get older we do not like handling heavy bales. We make our 14 x 18 bales 32 inches long weighing about 40-45 pounds each. The way we stack 32 + 32 + 18 wide = 82 inches. Our wagon bed is 7 x 14. We usually put about 100 bales on it. This keeps it easier to unload and very maneuverable in the barn. We put up about 700 bales this year.