Recently I picked up an early Ford double A frame. (Model AA dump version). I'm planning on using the rails only. The frame horns were missing and the rails will need to be cut to length since they are over 14' long. The wall thickness of the rails are 3/16" and the width of the rail is 1-3/4" at the front to 2-1/2" at the back where I want to make the cut. The rear frame section will be made of 2x3x .188 rectangular tubing. My question is, Do I need to box in the rails?