Trac-lock 410 will awaken the 4.0
Hi , If your looking for all around power & torque you all ready have O.D. trans. for milage.
I ordered my 2006 Ranger 4x4 Supercab with a tow package with 410 posi . It came with a louder larger exhaust system. The tow package came with 255/70/16 tires & alumin wheels. It has plenty of launch speed as it will run door to door with a new Harley Electro Glide till 50 mph.
I generally get 18 mpg. & will do 21 mpg @ 55 mph on a long trip.
I have 9 years & 27,000 miles of trouble free driving.