I'm looking to add a tool box and 50-90 gallon accessory fuel tank in the bed. I'd prefer two separate piece that would stack but have seen a couple combos. Anybody have recommendations.

Thanks

I have an RDS. Extremely satisfied. http://www.rdsaluminum.com/ Mine has a 51 gal tank ,toolbox up top, with it plumbed in to main tank

I also have an RDS 60 gal toolbox combo. It is a great product. Also plumbed directly to tank. I have about a 150,000 miles on tank. no problems.(you can figure out how much fuel flowed through).:D

I'll 3rd the RDS. I had a 90 gallon with the toolbox on the top in my F250 and really liked it. The short toolbox wasn't that great for big items, but you didn't have to dig to the bottom for the little stuff.

Does anyone know of a tank that fits under the truck? Not the enlarged tank that replaces the original, but an auxiliary tank?

I have Weatherguard 2 piece. Pics in garage.

Does anyone know of a tank that fits under the truck? Not the enlarged tank that replaces the original, but an auxiliary tank?

I don't . But on my 86 ford I removeed the spare tire and made a tank to fit in its place. I have been thinking about doing the same for Dmax. What I did was measure inside the frame rails ,had 2 u shaped pieces 5/16 steel braked ,welded a baffle on one then welded the 2 halves together. Also welded angle on either side to bolt to frame. I used a pick up from another tank. The only drawback was the fill spout came out behind drivers rear tire. It held 75 gals. I also had it plumbed in where I could switch tanks. Total cost was $125 using junkyard parts.

So there's an idea 4 u

Thanks!