I'm really upset. I have a friend w/ a 91 GT w/ a 8.8 in. rearend w/ richmond 3.73's and they make no sound whatsoever. I got Richmond 3.73's today and they whine when you're cruising and hum when youre driving really slow. I dont think they were shimmed right or maybe it's the crush sleeve that wasnt crushed enough or too much, whatever it is, I think i should take it back. The guy that did the install said that if they arent factory OEM, they will make noise, i find that really hard to believe. Will this whine wear away the teeth or waht will it do, just make noise and do no real harm? I'd love to hear some opinions.