you know, now i am really confused. i just drove by the tracker and noticed the solid axles. 
A tracker doesn't have solid axles.....at least not from the factory. Maybe your definition of solid axle is different from mine.
The frames are really nowhere near the same. The body mounts don't line up, the trackick frame arches up in the front and rear, whereas the samurai frame is relatively flat. The wheelbase is different (80" vs 86.6").
Maybe you are confusing sidekick with samurai? A sidekick and a tracker are the same basic vehicle and basically all the parts interchange.