Idler wheel bearings are common,the number is 6205,but if you have those Viper wheels that don't have a serviceable bearing you may have to get different wheel.From what I recall the early year Vipers had idlers with the bearing molded into the wheel and it was a throw away part once the bearing went bad,but perhaps there is a way to press a new bearing into those wheels,I've never had any experience with them.The rear axle wheels have a 6004 bearing in them.Bushings will be a dealer ordered item.