The majority of bows in spec with the cams in the proper orientation usually pull a couple pounds heavier than thier limbs rating number. So a 65 lb bow will usually be around 67lb maxed out. Completely normal.
Bows also have a spec range. If you look at a spec, like ATA On a Hoyt, it will usually say something like- 33" + or - 1/8". With my tuning with my own Hoyts I have found that they are usually dead on or a couple pounds heavier poundage when the ATA is right on spec.
Now, since a Hoyt is usually a couple pounds heavier right at spec, we still have about 1/8" of wiggle room for the ATA to twist cables/string and still be in spec. So we can twist the cables a couple turns apiece to gain 2-3lbs (to keep cams in synch, buss and control cables usually won't be twisted equally because they are different lengths under unequal loads) and then twist the string to get the cam timing (initial starting point of the cams rotation) back where it needs to be. Once that's done, fine tuning to cam synch may need to be done.
After this your ATA will still be in spec, and poundage will be close, if not at 70lbs. Hoyts limbs are very tough, and this is very safe if you stay within Hoyt's specs. Hoyt uses different (or the same) limb deflections for different poundages, on different bows. A 72 deflection limb may be 70lb on one riser, but 63lbs on another, depending on the limb pocket design. So changing Hoyts limbs this 1/8" is no problem whatsoever. Now you may not be able to reach 70lbs if your limbs are on the lighter side and max out at 63-65lbs. In that case you may only get 67-68 lbs while staying in spec.
Only do this with someone who knows what they are doing. Just putting twists in the cables isn't all there is too it, especially on a Hoyt. You're bow will also need to be retuned.