Hi,
I am glad you are considering Furman-it is a wonderful school -tremendous academics, professors and a great social experience. Your ACT score is certainly within the mid 50% range for, and your GPA looks fine. I know admissions looks strongly at course rigor-so if you have Honors as well as AP classes that compose your GPA, you should do well. Like many excellent LAC's, Furman has a writing intensive curriculum-especially in the first year with two required Freshman seminars. As our DD's first year writing seminar professor told the class last fall: "if you think you are a good writer, I will challenge that belief and make you are REALLY good writer."
Here is a link to the Furman institutional research section that can give you more information on the profile of the most recent admitted class:
Planning & Institutional Research: Common Data Set:. In looking at the GPA data for the most recent common data set ( 2008-2009), 42% of incoming freshmen had a HS GPA of 3.75 or higher.
Good luck on your application-there is a wealth of valuable Furman information posted on this board within the past 3 years-and loads of great information by parents and students who will be attending this fall.