Fuel Cell Frame Design

Hey folks!
We at HounDawg Racing are making huge progress building our next race car. Someday in the next four years, we hope to actually see some of you on the track!
While I finish up the roll cage and work on paint and body, I'm planning my fuel cell installation and I have some questions about design for the frame.
I see many examples where you folks have built nice frames that protect the underside of the cell--and there's no doubt that the more protection you have the better. But I don't see anywhere in the GCR or ITCS that mandates any kind of frame for the fuel cell other than the steel casing. You have to keep the bottom of the cell six inches off the pavememt--I assume your frame can hang down lower than that. So unless I'm missing something, as far as the rules go, I have the option of building a big strong frame nestled around the bottom, buying a kit like the RCI-7412A kit (looks like 1 inch by 1/8 inch steel strips that wrap 4 sides in two places), or (not that I'd want to do it) just letting the bare steel case hang down unprotected.
Apart from the rules, that are the design considerations for a safe fuel cell frame? First, I'd guess you want to cradle it firmly in place. Second, you'd want to protect it in case both your rear wheels fall off so the pavement doesn't dig into the cell. Third, the frame can provide some impact/crush protection.
Finally, have any of you running enduros with really big cells had any problems with ground clearance? Some of the 22 gallon cells I see can be pretty tall/deep. I saw an (old circle track) RCI cell, and if I installed it in my 240Z with the top flange sitting on top of my rear deck, it would hang down below the rockers. So if my rockers were 5-inches above the pavement, my cell would have to be raised 1 1/2-to-2 inches to meet the 6-inch minimum. That doesn't seem insurmountable--I guess you just build the frame and cover accordingly, but it seems like there'd be a better way.
Dawg



[This message has been edited by HounDawg (edited February 15, 2005).]