Ive had both Ford racing gears and motive 4.10's...I would just get the motive...I havent had any whine or any issue to speak of and I paid 99.99 for them on sale....Any gear will whine if installed incorrectly even Ford racing gears....If you get motive and have a good shop do it and correctly, they shouldnt whine. you also should replace the bearing and doing a full rebuild while your in the diff, or if you have the extra cash.....I paid 250 for install+oils+ 99 for the gears, and like I said no problems yet and Ive had them over 5 years with 30+ track passes. Youll be fine with yukon or motive gears. The thing with ford racing gears is theres less chance for whine and issues, because they are exact oem replacement so they are exact tolerences, which makes it easier for shops to install(no re shimming, re measuring, checking preload, ect), making it less chance for a screw up on the install.