Yes you can run bigger but remember bigger aint always better! Your not saying what size tractor you have and the BX 23 only has 18hp at the PTO. Depending on the snow heavy wet light and blowing, all figure into it. And running the rated blower will keep you out of trouble by not tearing up stuff while trying to move it around the place. I have seen 60 inch rear mounted blowers on like my BX and they might work but its not worth the extra money time and trouble you have, and most people will always try to take a bigger BIG BITE than what the machine will/can safely handle
Just MHO you understand I would say go with the recommended size