I have a friend who has what is probably a 150 gallon aluminum tank in the back of his pickup that he uses to refuel construction equipment. It's bigger than what you're considering and stands probably 12" or more above the bed rails, but I've known him for 6 years and he uses the tank daily with no problems.
My personal feeling is that since virtually all vehicles for the past 20 years or more (even my '91 Ford Ranger) have plastic tanks, you cannot go wrong with the plastic, especially with diesel.
I'm new to this site and it is very helpful. I want to thank everyone for their responses. As of now I'm thinking these plastic tanks are the way to go? To clarify my concerns about cracking welds, In 2003 I bought an aluminum L-shape fuel tank (110 gals.) for fueling up my farm equipment from TSC. It wasn't a month or so that it started to leak at the seam. I don't know what the quality of this tank was or where it was made? But it has been back in my mind ever since. Thanks again guys.
like any manufactured product there will be some failures. I have not had an issue once I figured there were two drains plugs at the bottom I needed to tighten, they shipped loose. IMHO you can go wrong adding extra fuel capacity no matter what tank you select.
