I thought a lot about this post today. Measure the box width. If you feel it was the one that came with the truck originally it will measure 46 inches if it is a 40 or 41. A jailbar( 42-47) will be 49 inches. I sure would like to see pictures of all of your equipment and the welding shop. It sounds like a fantastic place. I wish I had learned how to run mills and lathes and perhaps a waterjet cutter.I love this stuff.