I know this is an old post but I just went through the same ordeal with the Titan Drawers I purchased for my MN.
"It will fit straight in" he said, "Really easy to install" he said, "It only takes about 2 hours" he said.
Well it didn't fit straight in, and it wasn't easy, and it took me the whole day.
To get the drawers & wing kit to fit in neatly you have to put 30mm thick spacers under the frame that are also wide enough to spread the load over the ribs in tub liner or it will eventually flatten out.
Then cut 100mm off the rear wing angle bracket so it will sit flat on the guard. You don't shorten it, you just remove the thickness where it is folded down in a U shape for strength. Then it sits perfectly on top of the guard without any movement.
Then shape the wing lids to fit the side profiles of the tub.
Then extend & shape the carpeted ends by 100mm wide & 40mm in depth (at the bottom) with metal, I used 2 mm thick aluminum sheet. There is enough carpet left over from the wings to do this.
Also, you can put a piece of carpeted aluminum angle at the Cab end on top of the drawers to stop any crap falling down into the 20mm gap that ends up being left there. I had to buy more Utility carpet from Bunning's for this, a close match too.
I also neatened it up at the front with a piece of aluminum angle & glued carpet onto it & then cut to fit the tub profile, Otherwise you can see underneath because it is now raised by 30mm.
Anyway, it takes heaps longer than it should and you have to do a fair bit of custom fabricating to get it into a MN Triton, but it turns out pretty good in the long run.
Here is mine: