When I ordered my truck, one thing I ordered was a thirtyfive gallon tank. What a great option, you can not go wrong with a larger fuel tank, a larger bottle of Jack Daniels or a few more beers for the cooler.
If I had a 35 gallon tank, instead of my puny, stock, 26 gallon tank, I probably wouldn't have gone for the 52 gallon Titan tank I now have. I found the stock tank to be lacking by 5-10 gallons on more than one trip
Pros: It has a huge capacity. I can drive 800+ miles between fill ups. The tank it's self is very strong. I tore off the wimpy forward support bracket when the tank had probably 38 gallons in it. While I was rigging up a support for the forward half of the tank I didn't see any signs of distress in the tank, even with all that weight in the forward section of the tank. Because I wanted a lift anyway, how low it hanks (see cons below) wasn't a deal killer for me, but something others who are thinking of this tank should consider.
Cons: The Titan Tank hangs low. A local retailer told me it wouldn't sit any lower than the frame rail (which is already low on a Chevy). It turns out it hangs about 3 inches lower than the frame rail - not a good thing for off roading. It would be nice if the tank where designed to fit up into the frame cross members like the stock tank, instead of extending down below the cross member sections like this one does. That change alone would bring the bottom of the tank level with the frame rails. It has a poorly designed, weak, front support member.
Conclusions: Doubling one's fuel capacity is great! If you don't take your truck off pavement, this could be a great investment. Given how I use my truck, I may reinstall the stock tank an carry 2-3 Jerry cans instead.