Ron, I am reading your thread again, now the draw weight is posted. In my opinion you are already overspined for that bow. with that draw length I would probably go to 55/75 and run the brass inserts with weight tubes, that should get your weight up to where you want it. I have 2 Bear Grizzlies 55 and 58 lbs and I shoot the 35/55's out of them both, no weight tubes but with the 100grn brass inserts, I have a shorter draw length than yours but my gpp is roughly 8.5 gpp with my setup.Like I said my arrows fly like bullets.