Dave ,There's lots you can do in that gray area in between the rules,depends mostly on the tech inspector at the track. I've been involved in about a dozen metric chassis cars,don't recall ever snapping an axle.They must be made pretty well.Gm offsets their engines 2 in. to the right,putting it back on center and shove it back an inch or three. Lessens the need for rf spring rate by 150-200 lbs. I've gone so far as sectioning the cross member and moving the upper half around to hide my tracks,also moved both upper a-frame mounts 1/2 in. to the left.If they don't say you can't ,doesn't that mean you can? Hank