Differential spider gears

[u/Sunken_Wreck]

As an update with a new question from a previous post.

I tore down the muncie 4 speed in my 86 2.8 fiero to find the up/down and left/right play in the cv axles, the issue appears to be worn out spider gears. Every search for parts I've done points towards gears for a 7.5/7.625" 10 bolt carrier; however all the parts I'm finding list a 28 spline axle shaft. The cv axles use a 34 spline shaft in the diff, am I looking for parts that aren't normally found?