I bought a 2006 supercab PSD used about a year ago with 27,000 miles on it. The guy had a snowplow on it but from 2006 through when I bought it there was literally no snow in that part of New York, so I was not that concerned. I did, however, notice the lack of a front valance (the wind dam under the bumper). I bought one and bolted it on, but the fabric covering under the radiator with the plastic push pins still had no where to plug into.
So I located a simlar truck and had a look - it turns out the front crossmember is gone. It doesn't seem that structural in nature as it is only held up to the frame rails by two bolts. I'm getting one through the dealer and bolting it up next week.
I'm hoping that this is not a problem. I've been towing with it for almost a year. I assume this was removed to bolt up the snowplow.

BTW, the truck I located to check is sitting in a dealer's bay with the engine torn out. Something happened that caused a piston to weld itself to the cylender wall. Pretty impressive to look at. Not a good day for that owner. That truck is a 2005 dually.
Also I pulled the EGR this weekend to clean it, I was pleasantly surprised to find it pretty clean when it came out; I also installed an engine block heater cord. Technically easy but a huge pain to get it routed correctly.

 

The part you are referring to is called a blocker beam,and they typically need to be removed for plow installation.

Instead of buying through a dealer,check your local plow shops,bet they have a pile out back.

 

The bolts are already permanently affixed to the beam, so if you don't get them with the beam, you will need 6 nuts to attach the beam. 5 minute job.