Ford Repair: F150-4.6 V8 power enhancements, positive displacement blower, rear end gears

Question
I have a 2003 F150 Supercrew with a 4.6 engine and highway gears. (355 I think?)  I would like to know what I can do to the motor/drivetrain to enhance power for towing, and climbing sand dunes when out 4x4ing.  I am running 33" tires right now, and will be going to 35's by mid summer. The most I would be towing would be about 5,500 lbs.

Thanks!

Answer
Greg-

  Well...rear end gears are always a good option.  They'll increase your cruising rpm but it will make the car seem like it's got more torque for climbing and towing.  There aren't a ton of products out there for 4.6L truck motors.  Many of the mods that will work for Mustangs will also fit on truck, though.  The best solution I can think of for low end (and all around) power would be a positive displacement supercharger like the Kenne Belle blowers or an Eaton M112 (stock equipment on later model Lightnings and Harley Davidson F-150s).  A supercharger is certainly a bigger expense than many other modifications, but most other modifications are aimed at mid-high rpm power which is pretty useless for towing and 4X4 applications.  I'd say if you can afford a positive displacement blower (also known as a roots-type or lysholm screw blower...not to be confused with a centrifugal blower), that's definitely the way to go.  With a good kit you're looking at around $3700 or so plus installation but it'll give you a TON more power down low and is probably one of the best bang-for-the-buck modifications you can make.  Hope this helps.

Steve