There is now free software available to tune virtually any 99-04 ford vehicle, including your marauder. All you would need to buy is a Moates Quarter Horse and a laptop. Then download Tuner Pro RT and the definitions and stock tune file from efidynotuning there is lots of good "how to" on efidynotune too. Here is a getting started thread http://www.efidynotuning.com/started.htm
What this setup allows you to do over sct is, live tuning. You do not need to turn the car off to make a change to the tune. It is the greatest thing in the world.
I'm still looking for the base marauder tune on efi's site, but I plan to start playing with this soon.