custom classic trucks magazine, the latest issue has an article on a under bed tank with measurements. also placement of the filler. there is no date on the issue because of the address label covers it but on the front it says relocate your cab-mounted fuel tank and a blue and silver truck on the front. hope this helps. ron. i am planning on doing the same thing in the spring. but i have to move the exhaust system i just installed, duals, plus the brake lines are in the way. poor planning!!!!!!!!!!! ron