Def dif part numbers.
The 400TI has two dif bearings in the rear
Left side BEARING (6304Z)
96120-63040-10
Right side BEARING (6303U)
96140-63030-10
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The 550k has:
Right - BEARING (6304U)
96140-63040-10
Left side - BEARING (6305U)
96140-63050-10