I would caution against welding in that area of the truck. The first 16.5 inches of the frame have corrugations, convolutions, and intentional holes that are designed to be crush/crumple zones in the event of an accident. GM sells a collision repair Front "half" frame replacement part to replace just the crumple zones on the frames of these trucks, and they're very specific about where to cut and weld. Basically, if you look at the frame section forward of the front engine crossmember, that is the section of frame they sell. If you weld plates and ultimately a trailer hitch in that area, it'll reinforce the designed crumple zones, and could cause significant injury in the event of an accident. If you're building a heavily trail/off-road biased rig, maybe crash-worthiness isn't of such great concern, but personally, I'd go with a plate steel type winch bumper that bolts on in place of the stock reinforcement first.