Please, I say PLEASE don't weld any type of hitch into that truck.
Get something that can be bolted on.
I had a wonderful 2006 Dodge 3500. At least I thought so until I discovered that the previous owner, some good North Dakota farmer, had welded on his gooseneck hitch mounts to the frame on each side.
My fault for not noticing it when I purchased the truck.
The problem arose when I tried to get my fifth wheel hitch installed in the truck. Back rail mounts were fine, but there was no way to put the front rail mounts in it. Those welded in farmer made mounts for his gooseneck hitch were smack dab in the way.
Short version, the only way to fix it was to pull the box off the truck and grind off the old welding and mounts. And I could not find anyone that could ever do it. Or more precisely, anyone willing to do it. A few places told me that maybe they could do it, but maybe's don't cut it with me.
So please, please don't ruin the truck for the next owner. Sure, it will probably cost more, but do it the right way. Forget welding something on there.
ON EDIT: say partner, just thinking. You didn't use to own a 2006 Dodge Ram 3500 dually six speed, traded in to dealer in New Rockford ND????? :B