The 8 1/4 thread

If the O/D was bigger how did the caps fit them, was it because they was just wider ?

because the I/D was the same and I just bought new ones to fit the original 74 open carrier and seeing the I/D was the same they fit the new carrier just fine and fit in the case just fine as well because they were the exact same bearing as the one i took out/off the old carrier just new