that one (above) has good instructions and pics but it is for a wood floor bed, there are a few differences explained here
http://67-72chevytrucks.com/vboard/s...ad.php?t=82178
Or you can just pony up the money for a tank from that dang "fuelcellguy" with his fancy custom made aluminum tanks made to order between the rear frame rails however big or small you want. (yes I want one of his!!!)