One other option:
Find a used Apex or Nytro Timbersled Mtn Tamer kit, and cut down the width of the arms where they mount in the tunnel.
The Phazer kit is a cut-down Nytro/Apex kit. The shock part numbers are the same. I have a Nytro kit in my Nytro, and a Phazer kit in the GF Phazer.
With the cut down kit, you can download the Phazer installation instructions from the T-Sled website and install no problem.
Murph