onehot69stepside
+1y
what kind of c notch is it, if its 2x4 box tubing, all you have to do is use a plate notch. The plate notch would go around the 2 x 4 notch. you just trim the bottom out after you get the sides and top welded in. Or back half it with 2x4. Theres all kinds of back half pictures on here. Just cruise around and take a gander at em.