Possible Excursion towing Upgrades

Hi,
I am new to this forum, and will be gratful for any information you might help me with.
I own a 2001 Excursion with the V10 Triton motor. It already has the towing package I believe. Towing is rated at 10,000lbs when using an equalizer hitch. I've exceeded that a number of times (substantially) and the rig seems to have the power to pull quite well. The electric brakes are a must when I tow a heavy load.
I am looking to purchase a boat that will be a wide load (10.8') and weighs in at 12500lbs dry. Are there mods I can do to my Excursion to kick up the towing and suspension capacity, or do I need to start looking at a new rig?

Brother...

I would definitely look into a torque converter for the tranny. The stock transmission is not made to tow heavy loads like that. I have 6.0L PSD 2005 Ex... and I am very happy w/ the Banks Power System I have installed. You have a gas engine, but that being said, I would look into air intake and an efficient exhaust system. Engines have to breathe... In addition, look into a larger transmission pan, one that holds more fluid like a Mag-Hytech, and one that offers more surface area for cooling. Your transmission will definitely get warm towing that heavy of a load.

-Chris