Okay maybe I am over looking something, but the car now sort of jerks as I coast and the noise I am hearing sounds almost like the fans are on, but they are not. now I do have a header and when I let off the gas the noise goes away quite a bit, but still I can hear quite a bit of noise on the interstate, which I drive 120 miles a day to work. today I had the day off and I took the front bearings apart because I thought they were suspect. turned out they look good and bearing cage and races and hub assem. are full of good looking, clean grease. the wheel wont move back and forth on the hub so there is not wierd clearence or anything like that. the steering wheel jumps around a little and the vibrations in the gear stick are getting worse over the last 500 miles...or so it seems. are there any other things that could make noise at cruise speeds? Is the hub nut supposed to be loose when I got to it? I have filled the rear end with mobil 1 and the trans. too. Could the rear bearings be THAT worn? with the front wheels down on the ground, they seems to move back and forth, but the rears don't. all the lugs are tight. I'm stumped.