I looked this up on the parts microfische and it lists only one number for the early and late manual trans axles, meaning they fit left or right.

However, it lists seperate L&R numbers for the automatic (both early and late model) so they are not the same. It doesn't give specs on their lenght so all I can add here is that they are in fact different on either side of the late and early cars. Also, the early and late model part numbers are different so they changed in the series in Feb. '85 (late car).