Best way to raise the bed floor

[smashingchuck]

Alright guys, It's time to at least start thinking about the next phase of the truck, and that will be raising the bed floor. I'm not sure how to do it really. My original thought was to leave the stock crossmembers in, and space it up with 3"x1" x1/16 wall square tubing, but I really don't like that idea now too much. My major concerns are strength and form. The body work on my outer skins is already done so I hope I don't have to weld on those or atleast keep it to a minimum.

Here are my goals:
*I would like to run stock wheel tubs.
*I would like to do a flat floor, and have the inner bedsides run straight down on the inside. I know I will have to make a skeleton out of 1x1 but I'm just not sure what to attatch it to on the outside peremeter???
*I'm not sure exactly how high I want to raise it, but I was thinking 3". I would still have to run a separate raised "notch cover" if this was the case.

I cannot, for the life of me, figure out what to do for a fuel tank. I cant put it where the factory saddle bombs go cause thats where my air tanks are, my exhaust runs all the way out the back so theres no room where a blazer tank would go, and I really would like to conceal it somewhere rather than mount it to the inside of the bed. Any ideas on this??

any pictures, ideas on fuel cells/tanks, and ideas on how to attatch this new floor to the existing skins would be great. Right now the bed is assembled but all the floor/inner fenders have been cut out. The factory crossmembers are still in place.