Drilling through truck bed for aux tank

[NorthwestGuy]

A friend of mine who has a 2014 Ram 3500 dually has bought a 37 gallon transfer tankhttp://www.ocpetroleum.com/products/fuel-tanks/vertical-tank.html to go in the back of his truck right behind his tool box. This would be roughly a couple feet back from the cab. He is 80 years old and needs my help but I don't want to mess it up. Is there anything in particular I need to watch out for underneath when drilling the mounting holes? If anyone has any other tips I'd appreciate it.

 

[sbarron]

Fuel tank and lines, wiring harness, brake lines.. take some careful measurements above and below, don't forget that they are going to be mirrors of each other when you do... don't drill any deeper than you need to, make sure you paint any expose metal edges of any holes you make, insulate the legs with rubber sheet, to eliminate/reduce metal to metal vibration, and be sure to add extra support under the bed for the bolts with flat bar (preferred) or large washers to keep them from pulling back through. I'm assuming he'll pump from this tank into the existing fuel filler rather than a more complicated fuel system?

 

[NorthwestGuy]

Fuel tank and lines, wiring harness, brake lines.. take some careful measurements above and below, don't forget that they are going to be mirrors of each other when you do... don't drill any deeper than you need to, make sure you paint any expose metal edges of any holes you make, insulate the legs with rubber sheet, to eliminate/reduce metal to metal vibration, and be sure to add extra support under the bed for the bolts with flat bar (preferred) or large washers to keep them from pulling back through. I'm assuming he'll pump from this tank into the existing fuel filler rather than a more complicated fuel system?

Yes, this tank is for manual transfer only. One thing about this is that rather than remove the heavy toolbox to be able to access the front mounting holes he wants to use the mounting holes on the back only and then add a bar across the top of the tank that attaches to the bed rails. I'm going to try to talk him out of this since its not the way it is intended to be mounted and I think attaching it at the top and bottom will cause stress when the truck bed wants to twist slightly on uneven terrain as they all do.