[alsriv2]

Putting a tank in the rear is one of the things on my "list of to do's". I have seen many arguments for either direction, leave it alone, put it in back. I had a '67 GMC 3/4 ton many years ago and it had the in cab tank along with 2 saddle tanks, one on each side. I loved the way that truck felt and performed as well as the total distance I could travel without having to fill up.
Back to current discussion. Many seem to want to relocate to the rear for two maybe three main reasons. 1. Get rid of the smell of gas in and around the cab 2. Add some additional space behind the seat 3. add some weight to the rear of the truck for stability and such.
For me, if I was driving a daily driver, (like my previous '67) I wouldn't change a thing, but my current '69 is a nicer truck and with the 396BB in it, I will want the extra weight in the rear to help keep the tires planted.