I was able to spent some hours this week on my Chevy II. I fabbed some mini tubes this week. With the fuel filler neck originally running through the left inner fender and the large bulge this causes I didn't want to just move the original inner fender wells inward and fill the gap. The original rear inner fenders also have a generous radius that would cause tire clearance issues at full compression of the suspension or full roll. The scratch built tubs are made out of 16 ga. steel and there are two major pieces and two minor pieces tig welded together. I made a hammer form buck and used a shrinker/stretcher to form and shape the pieces. The price of DSE tubes doesn't seem so high now looking at the labor time I have invested but when you don't have a Camaro you are left with few options. There are more pics here
http://s250.photobucket.com/albums/gg247/ChevyIIPost/