As a result of the discussions regarding the gray tank in THIS THREAD I have been in touch with Rex at Northstar and with his permission I am posting his PM to me showing the retrofit and new design solution from the factory:
Here is what has been done to make this tank application secure. I took a photo of one with the frame not undercoated so it is more visible in the photo. The frame is screwed together, and then screwed thru either side with 1 3/4 and 3" screws. This solves any problems associated with the tank, and if someone would like a frame and a few screws we are happy to send them. It takes less than five minutes to install.
2005 Dodge 3500 SRW, Qcab long bed, NV-6500, diesel, 4WD, Helwig, 9000XL,
Nitto 285/70/17 Terra Grapplers, Honda eu3000Is, custom overload spring perch spacers.
2008 NorthStar Arrow short bed.
That looks pretty "cheesy" to me. I would have it made out of metal, like maybe some Unistrut or B-line channel. Wood seems to rot faster than metal rusts. I would also add a cross member. But that's just me.
1996 Chevy K1500 4X4 Short Box, 5.7L Vortec, E rated tires, Lance Model 820 with Cabover Struts, Firestone Ride-Rite Air Bags, KYB MonoMax Shocks, Torklift Stable Loads, Happijac Truck Camper Tiedowns and Turnbuckles, Honda Eu2000i Inverter/Generator.