The previous owner put a 30-gallon tank in my truck -- I love it, too! He put it where the spare tire mount was and did a great job running the filler over to the wheel well on the passenger side.

I believe he took the tank, as well as the filler door, from a mid-70s Cadillac.

I have some pics Here

And a couple more pics Here

~~ Alan Horvath
1954 Chevy Pickup
Singing his praises in the
Passing Lane