Towing Issues: towing auto vs manual, tow package, trailer weight

Question
I have a 2005 F150 4.2 V6 regular cab short bed XL. Was wondering 1.Why my tow rating is less than the same truck with an automatic? 2. How much trailer weight can my truck really tow with a complete tow package with stabalizers? I only need to tow one time about 250 miles.

Answer
I answered this once before, but maybe it didn't go through.

The manual trans version of some vehicles has a lower tow rating than automatics usually because of the capability of the transmission.

How much it can tow with a different package depends on the package, and I can't estimate on aftermarket options like stabilizers (on the springs? on the hitch?).   

The tow rating probably won't go up with a tow package because the limiting factor is probably the transmission.

Don