Is your bow maxed out in weight? Adding 5#s of draw weight could get you the extra 8 fps you want, but in reality, 8 more fps won' t make a hill of beans difference to your current performance.

What' s on your string? If you have a kisser, peep, peep tube, etc, getting these off will pick up fps just like lowering your arrow weight will.

But if you' re satisfied with the current shootability and grouping of your bow now, I doubt you' re gonna see much if any difference from 8 more fps.