In case anyone stumbles on this, it does work just fine. I used the KX250 wheel spacers and cannot speak to KLX wheel spacers since I did not have them.
The bolt pattern on the sprocket is the same but the disc break is different bolts and pattern, so replacement discs would need to be spec'd for the KLX. But, it is the same diameter and disc position so no worries about it working.
Tom