I read on here somewhere that there's a header in there. When I mounted mine though, I found out it's an aluminum header. So it's not as helpful as you first think. The bottom of this link is how I did mine. Looks great when the flat screen is up and it's been hold up just fine.
//heartlandowners.org/showthread.php/15385-3612-Shake-Down-to-Gatlinburg-Tn?highlight=