Your model has Cold Air Intake(CAI) already, and it has scavenging "headers" for more mid-range power, you could replace these with low-range headers, but you do lose mid-range.
Replacing mechanical rad fan with electric frees up a few "ponies" isn't much but isn't nothing either, also better MPG, so win-win, power and economy.
3.0l is a high RPM engine, it makes highest torque at 3,700rpms, a 4.0l has highest torque at 2,400rpm, so you do need to get the RPMs high and stay high to get any power from the 3.0l.
If you drive it like a low RPM engine, i.e. the 2.9l or 4.0l, it will drive like a slug
Breaking the tires loose is torque not horse power.