Need help identify axle

?90 axle in a ?81 240

Just double checking if a ?90 axle will fit my ?81?

Meaning... will everything swap over without issue? Brake assemblies, brake lines, driveshaft... etc.

I am planning to go swap the gear ratios to a 3.31 and install a TrueTrac

Here is a pic of the axle.

Has the ears, so should be 1031.

Dunno the springs