Ramcharger gas tanks are 35 gallons. I've got 2 installed on my crewcab project.

 

These mount where our spare tire resides or along the frame?

Bill; with the larger intercooler I think I have lost some cooling abilty already. Gets pretty warm with a/c on and 10,000 feet, although, it would help deter damage from the occasional deer/bighorn sheep/elk/moose.

 

The original ramcharger gas tank would be where the spare tire is located at on the pickups. I'm running 37s on my crewcab when it's finished so a spare will not fit there and I had an incab gas tank on the truck. The second tank is still under the bed in between the cab and the goodneck mount. I had to make completely custom brackets for that. The back tank uses all stock ramcharger brackets. There are pics in my website. The link should be in my signature.