I have a 8.75 741 open and 741 clutch center section and a 489 cone style center. they all appear to have thrust spacers in them except the 741 clutch ones are much smaller in diameter than the other two. The small ones are about the size of a dime and the bigger ones are the same diameter of the axle shaft. Is this correct? And if so, can it be run or do they or the axles need to be changed? Thanks.