FLL Immigration and Customs are currently taking 1:00 to 1:15 to clear based on the tracking of flights we do for pickups in FLL on International flights. All International flights arrive in terminal 4 and the new customs area is in the area above concourse G. After clearing customs, you can go back through security at terminal 4 and cross behind security to terminal 3 or walk around the outside at the departure level. B6 does not have many flights departing around 8 pm so security lines should be light.

Just hope you won't have any suspicious items coming into the USA that might have you go through secondary inspection, and you should be fine.