I could be a dick and say that you linked him to the wrong cover.....but I won't do that.
Jim posted the other version of the 6000 cover, completely the same in purpose, only difference being the smaller 6000 lettering vs the large letters on the one he posted. There is also a 5300 version, the caddy version, and the version that I use (the Vortec MAX cover).
I can dig up the part number from the Max cover, or you can check my build as I always spam saying. I bought all 3 new from either GM parts direct or Nalley GMC, I'd have to double check. The price for all three was under $100. I chose to customize mine a bit, but all of them fit the same (but if you run DBW make sure that the top cover clears the TB. it has a more aggressive slant on the front plastics, and the non-dbw covers rub the TB)