[Magsrgod]

For whatever reason I'm having a hard time determining exactly what needs to be done to extend a Fox 40 /w Air Spring from 190 to 203. Ive been looking all over for air shafts like I'd use in a 36 and I'm coming up with nothing. Does anyone know if there is a spacer or shim inside to reduce travel and its as simple as removing them?

 

[eshew]

You should have a code/serial somewhere on that fork.

Enter the code on this site, it should link you to whatever compatible components there are. If that doesn't work, call fox

https://www.ridefox.com/fox17/help.php?m=bike

Although it looks like the only difference between the two is just a threaded shaft that can be replaced. In the pic below you can see the long thin shaft has 2 part numbers corresponding to different travel.
P/N 229-10-409: Shaft, FLOAT NA 2, Internal Thread, 40 203mm

Although you may want to confirm with fox if that is the most updated shaft for your fork.

 

[Magsrgod]

Awesome, I don't know how I missed this diagram through all my searching!