I got a 95 4.6, and one days was like "screw it" let me do this (being that i've read so much about it).. It took me about 20 minutes, and i did notice the cars throttle response was a "hair" stronger. You will hear a "WIIIIIISSSSH" noise at full throttle...which sounds good.
BTW, i didn't notice squat on my gas mileage. While your doing that, take off the entire intake and clean her up good...get some throttle cleaner and clean up all that black carbon on the throttle plate, along with changing your filter. I bet the car will thank you.