Several people have asked about the specs for the different u-joint sizes. The June 2004 issue of Four Wheeler has them listed.

Series 1310

overall width=3-7/32"

bearing cap diameter=1-1/16"

Series 1330

overall width=3-5/8"

bearing cap diameter=1-1/16"

Series 1350

overall width=3-5/8"

bearing cap diameter=1-3/16"

Series 1410

overall width=4-3/16"

bearing cap diameter=1-3/16"

It list some other relevant data such as load rating also.