Hi Bolters, 4 years ago I bought a 51 gmc one ton with a a long bed that was used to haul grain in Canada. It still had the grain box on in the pick up bed which I removed. There were two layers of 3/8” plywood on the floor with the original bed under that. The original bed was pine and other than a shattered back corner (looks like someone dropped something too heavy) it seemed intact. Then I saw the burn hole on the driver’s side just above the axle. Being new to the truck I wondered how that could happen. There was no charing of the plywood floor on top of it, so I believe the burn happened before the grain box was built on. The interesting thing I noticed is that the burn was from the bottom up. I’m sure some of you know exactly what happened since that is where the exhaust pipe bends up and over the rear axle and is closest to the underside of the bed Two things I’m happy about: first - that the truck survived this close call and second, that after surviving, someone converted the truck to a dump. That meant removing the rear bumper if it was there, clipping the frame and adding a pivot pipe. Adding rams and adding two white oak stringers which raised the bed 2 inches. Disconnecting the rear fenders from the running boards freed the box to be able rise up and most important to this note - diverting the exhaust pipe from the rear, to the drivers side at the rear of the running board just ahead of the rear wheel. No longer was the exhaust anywhere near the bed or the rear of the truck. An important feature when hauling grain. So the reason I felt it helpful to write this is to make you aware of where these beautiful new beds can be vulnerable. I think I saw somewhere that a heat diverter plate is available. If your truck is being used hard, crawl under and check things out. If you’re rebuilding or building new make sure the bed and its new finishes have adequate room from the exhaust. The two pictures included are the top view of the burn hole and then the bottom side.
