It is possible, but i hear you have to modify core and client files ... i speak about trinity core ...
PHP Code:
enum LevelLimit
{
// Client expected level limitation, like as used in DBC item max levels for "until max player level"
// use as default max player level, must be fit max level for used client
// also see MAX_LEVEL and STRONG_MAX_LEVEL define
DEFAULT_MAX_LEVEL = 80,
// client supported max level for player/pets/etc. Avoid overflow or client stability affected.
// also see GT_MAX_LEVEL define
MAX_LEVEL = 1000,
// Server side limitation. Base at used code requirements.
// also see MAX_LEVEL and GT_MAX_LEVEL define
STRONG_MAX_LEVEL = 1000,
};
