Also,
any more detailed on this? Pics? Where's this lower black tray?
You will have to take off the lower black plastic tray. You will have to cut off the ends and it will look pretty much like this. You have to trim it for the pipes to clear. If you ever go back to stock this will be hidden by your bumper skin.
The tray is held on by 4 bolts. Since you cut the ends of the tray you don't use the threaded welded nuts on the outside. I would recommend you trim the thin sheet metal the holds the welded on nuts. It's a very thin piece of metal in front of the seam and a 1" wide. You can use a hack saw, pliers, tin snips, etc.. to remove. This will help the pipes fit up higher. Now get this 2.5" pipe. This is also the pipe you can cut on the straight section near the top to give extra clearance for the taller batteries. Try it first. Then cut if needed.