Nice looking ride you got there.
Don't know what your plans for it are, but a Superchips engine programer will unleash the inner beast in that 5.4 (along with cold air intake and good exhaust to let her breath, but I digress). The 5.4 comes soo gutless outa the box(relativley speaking), a programer would increase yer' horse and gas milage.
best part about it, Is that the programer itself stores your stock configuration when you use it, So if ya need service, just plug it into the OBD port under the dash and return it to stock configuration. takes all of 2 mins....
best 330 bucks you can spend on a new motor. You'll be into it for just under a grand is ya go the intake/exhaust route.