The carrier bearings for the 8.8", solid axle or IRS, are now under XW4Z 4221 AA as the latest Ford part number. Should be around $10 each from Ford. The cups for IRS cast iron housing, and solid axle, are D9AZ 4222 A, also around $10 each. If you're using a Mark VIII or Cobra aluminium housing, the cups are different, Ford p/n is F3LZ 4222 AA.
cheers,
Ed N.