T-case input gear

[Todd Thomas <tthomas@domain.elided>]

Does anyone know how to tell a Dana 300 and a Dana 20 input gear apart?  Do
they have a different number of splines and if so what are their numbers?
This is for a T-19 trans although that should not matter.

Also would a T-19 from a ton 2wd truck have the same output shaft as a T-19
in a scout.  Without dropping the T-case I can not visually compare. 
Todd Thomas
Hopkinsville KY