3/4" x 1 5/8";  special for Carter, plus Kartco 7664.
(Picture is representative of, but is not, actual product.)

Dimensions relate to diagram at bottom. 

Please note:  Many sell a replacement bearing that is only 7/16" thick and call it a "G903."  The G903 is 1/2" thick.  It also has to be sealed on both sides. 

This bearing is a replacement, but it has the same specs as the original Carter bearings.