I have great results on my 4 Banger, with all its mods, accel coil, accel 8mm wires, NGK plugs gapped at .037, HOME BREWED cold air intake, bigger air tube which is insulated, 4.0L TB bored to 57mm, Custom TB Spacer, Bored out manifold intake, Magnaflow muffler, and free flow cat. All these little mods add up as a whole and not one mod by itself is going to perform well without the other. NOW about the MODIFIED STOCK AIR BOX. I have through trail and error experience that you can manually fine tune you air intake. Of course I have a k&N flat panel filter, and the front of the box is cut out along with a heat shield from the box to the outer edge of rad. I have also removed my headlight bezels. I am getting ambient air from around the headlight right into the air filter box. The removal of plastic chrome rings on my rig looks pretty cool, I guess its because my jeep is white and it gives it that competition look. BACK TO THE AIR BOX. I also cut a hole on the bottom of box which is a exact macth the the hole in the metal fender, right where the upper shock mount is. I have never had a problem with water or dust due to the shock mount acts as a shield. I am getting instant availible air from this bottom hole for crawling or off the line. Now I also cut out the right side of the box, but only towards the front half. So I get instant air from bottom hole and ram air at higher speeds from front and side of box. I have noticed air presure is built up towards the back of the box as I go faster. This is good. Lots of air but keeping it pressurized. I did one more thing. This works really nice. I cut to shape a plate that fits the side cutout n the box that slides back and fourth. It has a slotted hole to allow any adjustments. It has a thumb screw for quick and easy adjustments. I can fine tune my air intake either for faster take offs and real smooth response, or for more torque by closing the sliding plate a bit. I have noticed that any small increment in the slide makes a big change in response. Its like I can adjust my torque. Or adjust for MPG. Or just the right sweet spot. I just think how can one aftermarket cold air intake fit all power plants with different mods. Do we all have the same modifications on all our engines, or do we need taylored air intake for your specific engine upgrades. ADJUSTABLE POWER & TORQUE. WORKS GREAT. Happy 4 Wheeling.