My Excursion is a 2002 that was lifted six inches and now has 37" BFG Mud Terain on Moto Metal wheels.  The stock V-10 was removed and a Cummins 12-valve was swapped in.  The turbo was upgraded and the engine intercooled using a stock Ford intercooler.  The injectors were also upgraged to POD injectors.  I have not yet had it on a dyno and don't want to guess at the horsepower or torque.  I do know that my mileage is now averageing 17 on the highway and 12 pulling my toyhauler.  A custom rear bumper was also made for a full size spare tire.