My wife's arrows are 600 grains, 28 inches of Douglas Fir, with a 160-grain Ribtek, with three four-inch fletch. Her bow is 52 pounds at her 26-inch draw length.
She kills Big-bodied Idaho bulls dead with that combination, but her arrows never penetrate the other side.
If you are using carbons, just keep it over 600 grains, use a great two-blade head (preferably 160-grains or heavier) and you should be good to go.
Do not under-draw. At that weight, it's best to put every thing in your favor. Squeeze those shoulder blades man, squeeze those shoulder blades. Elk season only comes once per year. . .