Wow, short short bed F150's are not the best for towing a large trailer. With just me in the truck, everything balances out OK, but with wife, two kids and my mom, I was 500# over the rear axle rating! My rear axle came in at 4500#, door sticker GAWR is 4000#. I was going to drop the trailer on the scale, but after 2 pulls for bars on, and off, in 90+ temps, I was done. I got what I needed to know.
My tip for anyone who doesn't have a trailer yet, load up everything you plan to take that would not go in the trailer and go weigh the truck. Do it again with just you in it, subtract the difference and compare it to the laywer tag on the door, and see what you have left. Chances is are, you wont have much at all with a 5.5' bed. That rear seat is too close to the rear axle.
A lot good having a 14,400# GCWR when you can't get a trailer hooked up without exceeded the GVWR of the truck.
