I know round tube is stronger in more directions and more desirable for a roll cage, but what about making the whole chassis out of square tube? (kind of like what the guy in this link did http://myweb.tiscali.co.uk/dennisdoyle/my_mallock.htm, except it would be fully enclosed like a conventional buggy). I would figure if you had enough shapes and triangulation it could be pretty strong.

check out HydroDynamic's build thread (http://www.pirate4x4.com/forum/showthread.php?t=585331&highlight=build). Pretty much all stainless steel square tube.

And as far as square vs round tube, round tube is easily bendable making it better for a cage, square is REALLY hard to bend. theres a thread on here somewhere about square tube vs round tube, i personally like square more than round thats why im making my trusses, driveshafts, and anti-wrap bars from it :smokin: