FYI - you may have to trim the new filler tube a little, so keep the old one as a template. I had to trim mine because it was hitting the bottom of the bed after I installed the tank. (the new tube was a soft rubber and very flexible, as the stock one was rigid and not very flexible) I didn't check and I was in a hurry to get it finished.
(I found this out later the first time I filled up because I could not get any gas into the truck. the filler tube was kinked and wasn't venting right. I got more gas on the side of my truck and on the ground, than in the tank!)