yes it is legal, I would not run radius arms in that environment, our rig is full traction, cage tied to all suspension, eveything reinforced, every seam on the unibody grinded and welded, trussed spooled 35-spline 9", hydro bumps on all four corners, they failed to address the shockmounts, got a pre-bent cage that ties only to the floor, etc etc. I was extremely disapointed in that show. That thing will not only be undergeared but will crack in half, soon if they try to race it. Ours has taken over 12-months to build and it is another few months until TESTING, much more to building a capable desert racer than what they covered, hopefully it will do better than the Ranger they built, but doubtfull. Anyways good to see coverage.... at least.