Well it looks like you can definitely run under 55.xx and probably faster. Being a left leg lead will give you an advantage over right leggers, but you really should do your best to learn to hurdle with both legs. This will allow you to move to an even step pattern (ie:16 steps) at some point during the race. Doing so can really help with maintaining a comfortable stride pattern later in the race. Otherwise, going from say a 15 to a 17 step pattern, you might feel like you're chopping all your strides in between or slowing down too much.
Other than that, my above comments still stand. Best of luck and keep asking if you have questions.