RE: Limbs ( #'s )
When they bolts are the are tight you are at max. You can be above or below the 60# rating that is listed for that bow. Typically, the bow is over. My bow is rated at 70# but when bottomed out is at 75#.
If you are below then you can add twists to the string to get the bow to 60#'s without necessarily changing any of the other characteristics if the string/cables have stretched a little due to shooting. You can check your ATA and it will tell you if you need to add twists.