I have an 09 rtx se Cobra track, extroverts,160 1.45 megabites. My current set up is 1 bolt 4 washer in shoulder, 1bolt 1 washers in center,nothing in tip or overdrive. The sled pulls hard but only pulls 92mph on a long run but revs to 9100. I think it should be more like 8800 to 8900 on top...