I have a question regarding the tow capacity of my 06 XLT (V6) 4x4. I have a travel trailer (appx. 6,000lbs) and I currently tow it with my F150. We live in a huge hill and our driveway is asphalt up to the garage and gravel beyond that (100' +/-) uphill also. I can't use my F150 to back the...