Could you explain how they didn't fit?
Are you sure you mounted them the right way?
The seal should go in towards the diff, the widest part on the bearing being towards the brake assembly.
Actually I installed one the wrong way the first time, thinking the oil seal should be outwards, causing the bearing to not seat properly.
As I said, I've been using the Centric equivalent with no issues, and the specs for them are exactly the same.