I have a 70lbs tv 27inch for my cab.  I have the cab from the Project Arcade book (Lucid style).  My monitor shelf has about a 14-15 degree angle on it.  COuld I just rest the TV against the back part of the cab,  aka the upper back section?  Or should I put some wood in there to prevent it from sliding around?  I won't be moving the cab once the TV is in there.  
Does anyone just have it where the TV is in there?  With no big support wood?