This is my 5th wheel rig that I tow with my 2007 F150 V6. These light weight single axle trailers are hard to find. The 5th wheel is the way to go when you want a an easy to handle rig.
I live in the West so I have lots of long uphill grades. This truck/trailer will pull the normal 6% grades at 45-50 mph. Downhill is no problem either, I only have to touch the brakes occasionally.
This rig is right at the rated GCVW of 10,000#.

 

Do you have a transmission cooler? The engine is no problem with the V6, but I'd be concerned with the smaller automatic. Perhaps you have a manual trans?

 

Yes, I have the aux trans cooler. BTW this truck has the same transmission as the V8 150.