The following is an item for the FAQ on tanks I put together while researching and installing my tank. There was a lot of information out there, but still a few questions that weren't answered. I wanted this to be an encompassing item using George's write-up (link below) as the starting point. Feel free to point out corrections, clarifications or add other methods, other tanks or just show us your setup. One of the popular modifications these days is to add more fuel capability. Additional fuel means more range. There are several choices to choose from depending on what you want. There are several things to consider when making this choice: How much range do you want. There is the 13 Gallon OEM sub tank and there is the 24 Gallon, 38 Gallon, and 44 Gallon Auxiliary tanks. Clearance - The 13 Gallon OEM Sub Tank tucks up above where the spare tire goes and provides no clearance issues. The 44 Gallon drops down below the rear and does impact clearance. I know a few who have smacked their 44 gallon tank on the rocks. The 24 Gallon provides a nice compromise. Modifications to allow tank. Some rear bumpers with hitches have assemblies added under the truck that require modification to allow some of these tanks. The Slee Rear Receiver brackets for towing would need to be modified to allow the 24 gallon, 38 gallon or 44 gallon tanks. Cost - The 24, 38 and 44 gallon tanks are sold new in kits and can cost over $1000 with shipping and additional odds and ends. Rarely do any of these tanks come on the market used. The 13 Gallon OEM Sub Tank can be found used for less money if your patient. There are 4 main components to any additional fuel tank. 1) The Tank, 2) Dual Filler Neck, 3) Transfer Pump and 4) Electronics. The electronics and Dual Filler Neck is pretty much the same for all choices. You can make your own electronics or you can order the ECU developed by George (George_TLC) in any of the applications. The Dual Filler Neck is one of the most difficult items to procure. As a last resort, you can get it from an Australian Toyota Dealer for about $375AU. The interesting thing about the 13 gallon sub tank is it is a Toyota tank designed for the 80 series. This comes installed from the factory in Australia and several other countries. However, this is not an option you can get in the US or buy parts from a local Toyota dealer. The ribs of the underside of the truck are formed to fit the tank. There is some existing wiring in the harness that can be used. There are some holes with captive nuts that can be used to install the transfer pump and the two most difficult holes to install the brackets are pre-drilled. George has an outstanding write-up that can be found here on installing the OEM 13 gallon Sub Tank. This write-up was used by Boston Mangler as the basis for his 44 Gallon installation and write-up. I want to thank both George and Kevin (Boston mangler) for there excellent write-ups, they helped me and others in this process. George's OEM Sub Tank Write-up Boston Mangler's 44 Gallon write-up I also want to thank cruiserdan, clownmidget and Cruiser804 for help they provided in this effort Here is an excellent write-up on a 24 gallon install https://forum.ih8mud.com/showthread.php?t=104791 George's write-up is referred to in many places in this FAQ for details and pictures. It is recommended that you use his write-up as a starting place and then this FAQ and other links to augment his procedure.