tore my car down 4 years ago, put it back on road today after Canadian Mustang "big Kit" install and underside detailing, and noted what i believe is a wheel bearing problem that i did not have prior to teardown. also changed rear end lube and properly filled with specified lube. car has 7 1/4 2.83 rear in a '68 6-cyl with a rear end tag of WCY R X Ford 2.83 8 EA 903 (never could decode X which is not on Specifications page of Shop Manual. the noise is a low frequecy grinding and with wheels and drum off can feel roughness in each wheel but no play and with hubs turning on jackstands can hear it from wheel end of axle. almost sounds like bearing is dried out but i assume it is permantly lubricated. any ideas anyone.