I just got my mosers axle last week with 5/8 studs.i have wilwood rear brakes but like Bill said u won't need the moser retainer you will use the black retainer that hold the caliber to the housing.also if anyone going to use 5/8 studs will need the drill the 1/2 hole with a 11/16 drill bit which I felt spending that kind of money that should be an option when one order the brakes