I have an allegiance that at 62 pounds draw weight and 29 inch draw length shoots a 310 grain arrow 318 fps. This is shooting 5 grains per pound the same as IBO test specs.

Now add another inch of draw length with equals roughly 10fps puts you right on 328[8D]

IBO test specs are 30 inch draw length 70 pounds 350 grain arrow. (5 grains per pound)