Originally Posted by
krayZpaving
55 mins is definitely enough. And AC will guarantee to get you home anyway - they've sold a connecting ticket so if the inbound is late, they'll get you on the next flight (which is generally an hour later or, if you have flexibility to go to City Airport, 30mins).
OP is not destined to YYZ, he is inbound from YYZ and destined to MCO. Of course AC will reroute him to MCO, but that is not the question.
Does OP have checked luggage, NEXUS, does he anticipate any immigration issues? Those are the holdups for pre-clearance stations.