Hey everybody, looking to replace my OEM 23 gallon fuel tank with another tank under the cargo area for belly clearance and a 4-link setup in the future.

Just wondering what's the easiest way to do this. If I get a custom tank made, is it possible to reuse the factory fuel pump/sender as long as the new tank is the same internal height? I think the biggest issue with this is mounting/sealing the pump unit on the new tank, therefore using the same threads for the bung. Are there any other problems I might run into? I can buy a tank and pump assembly on ebay for pretty cheap to get all my measurements and sell them afterward.

I have seen where 3rd gen guys swap to a Ford tank (18 gallons) but they use an aftermarket fuel gauge. I would prefer not to do this as I think my idea should work well, and I can have a custom sized tank to fit my 4th gen (~23 gallons), it will just be more expensive.

What do you think?

OK, I found this fuel gauge interface module which I think is programmable to match up ohm readings between the stock fuel gauge and any sender.

https://www.summitracing.com/parts/cin-sn34

Thinking about fuel tanks from Boyd's welding.

Universal Aluminum Gas and Diesel Fuel Tanks

Can't add much, but I am curious to see what you discover. If you find someone that can make a custom tank that fits where the factory spare sits, I bet you would have a fair number of other people who would also want to pick one up. I know I would love to add one as a 2nd tank so I can ditch the jerry cans.

I've been researching this for a while and haven't come up with anything. Any revelations?

Been researching here and there.

Easiest swap would be to the FJ fuel tank but lose some capacity. 19 vs 23 gallons. I have a 1.5" body lift, and once I 3-link it I could mount it above the frame rail a decent amount. FJ tank has a built-in plastic skid plate too, which is light weight and strong enough especially with it mounted so high.

I removed the tank on my Tundra, and learned a little about some of the connections and routings, and it doesn't seem too tricky to build a tank from scratch either, using a factory sender/pump unit. Not sure that is necessary though like I said the FJ tank should be plug and play hardest part will be mounting it. And then possibly fabricate a secondary tank behind the axle which feeds into the main tank with the flip of a switch. Would only have to hold 6 or 10 gallons.

Check out dirtco's thread in 3rd gen. He added a tank and has some pictures and good discussion. His is a HIGHLY modified 3rd gen to say the least!

I'd love a larger tank