The stock step rails would just bend (they are pretty weak) into your rocker panels.
I actually wrecked my original step rails while driving on 880.
Pictures:
http://community.webshots.com/photo/33569671/32111542UcXQjtCEIO http://community.webshots.com/photo/33569671/32111671bbePvXPaHU It pushed my step rail up and back. It was about 1 inch from touching my Rear tire.
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