How do I fix this?????

[aany001]

I assembled my shortened diff with everything on it down to the wheels and I trimmed down my old axles just for mock up purposes and all I have for clearance on the inside of the tire to wheel tub is 1/2" and 1.25" on the outside.Basically the overall length is 1/2" too short I think.
What can I do and what are my options????