I know you don't want to hear this but get a new rest. These are a nightmare to tune with complete fletch clearance. That is why the newest and hottest rests don't look a thing like that one....and why the prongs were turned. I have had guys bring me bows that they did the same thing to. I would look at a whisker biscuit if you are going to hunt whitetails. They hold the arrow and are very accurate hunting rest. You got your set up used I am guessing so therefore you saved enough to spend $35 on a rest. That is cheaper than a new dozen arrows you will need if you keep shooting the quicktune!!
Once you get this problem solved come back and we will try to help you get on track.