You don't even need to weld. It is like 1/2 per side angle iron. Just cut and drill. The stock one hole on ones side and has holes for the super long stock battery and a normal sized battery on the other. Mine had washers and double nuts for the J bolts, but I am not 100% sure what is stock. The battery wedges up against the ridge in the battery box and the angle iron goes on the other side (toward the inside of the truck).
*not legal advice*