Outlaw 76,
From what I have heard, the optimal arrow weight as rated by IBO is your draw weight multiplied by 5, so in your case, 325 grains, which would include your tip, fletching, nock and insert. Any less than that, your bow simulates a dry fire. Significantly more than that, you are loosing a significant amount of speed.
I would have the arrow weighed with the fieldpoint or broadhead that you shoot and see where you stand relative to the 325 figure. I shoot Carbon Express CX200 arrows. The GT Expedition Hunters weigh 8.2 grains per inch, so if you shoot 28 inch arrows, they weigh ~ 229.6 grains + fletching + nock + fieldtip. I am pulling a 64lb draw weight, and my total arrow weight is between 325 - 330. I am getting about 275fps at a 27" draw.
The Parker is a nice bow. I used to shoot the Phoenix model and really liked it. I am now shooting a Bowtech and also like it. Anyway, best of luck to you.
Cordially,
Weatherby