The pic that scott showed is the way my 75 23cc was set up. No bulkheads on the front or rear of the tank. There were 4 90 degree angle legs that were screwed into the sides of the stringers. There were some wood shims between the legs and stringers. Most of these were rotted and barely holding the tank however to my suprise the tank was secure. I like Pascoes method of securing the tank with runners under it to allow for air circulation
http://www.casdvm.com/photos/Gas%20Tank%20Support/
however after I glassed these runners in place I found that the tank was 3/4 inch too high and I could not get my deck hatch back over it. I then proceeded to remove the glassed in runners and my solution to secure the tank was to 5200 it to the deck. It is solid and not going to move. It may be a pain to get out later but then again it's a pain to remove a foamed tank and I did not want to put screw holed into the sacred seacraft stringers [img]/images/graemlins/grin.gif[/img]
Strick