I have a 165hp six cylinder car that pulls 800lbs without a problem. There is not a lot of torque but it works well over a long haul. I think you will find 65mph to be the ideal speed for engine. 70 isn't a problem but the engine seems to work easier at only 5mph less.

Your biggest concern will be negotiating the kamikaze traffic on Hwy. 98 unless you head straight north to I-10 from Navarre.

Then, if you're coming south on I-75 you will have to check your rear view mirror for almost as much time as you spend looking out the windshield. Since the inside lane is going 80-85mph and the outside is bumper to bumper tractor/trailers you will have to use the middle lane which can be exciting because the middle will be populated by the frustrated tourists from the inside lane and frustrated truckers from the outside lane