Well, I'm just about finished installing my gas tank. Most of the tank solutions I see don't work for us 3/4 ton guys because the 3/4 ton frame is about 4" narrower than the 1/2 ton frame. I wandered through the pile of gas tanks at the dismantler where I got my engine, and found a tank from a '70 Suburban that measured about right to fit up into the frame behind the rear axle. My space is a little narrower than a stock setup, because I moved the new rear end back 1-1/4". Here's a picture of the tank, modified for an in-tank fuel injection fuel pump and with a 90 degree muffler bend welded to the inlet.
[img]http://www.brakecylinder.com/images/52chevy/gastank10.jpg[/img]

Here it is in the truck.
[img]http://www.brakecylinder.com/images/52chevy/gastank01.jpg[/img]

The flange of this tank has angle reinforcements welded to the sides. I decided to drill these and bolt them to 1/2"x1"x2" spacers, then bolt the spacers to the frame. It's heck for strong. If it hadn't had the reinforcements, I would have strapped it as usual, but this arrangement works very well with this tank. Here are a couple of shots of the mounting.
[img]http://www.brakecylinder.com/images/52chevy/gastank02.jpg[/img] [img]http://www.brakecylinder.com/images/52chevy/gastank03.jpg[/img]

Due to the 8 image per posting limit, I'll continue this in Part 2.

Joe