Hi Bob and welcome to the forum.
The cross members that screw to the hull are attached at the gunnels. On the '07's they screw into some brass plates that are rotomolded into the hull.
The '06 does not have these plates and access, particularly to the aft gunnel region is limited. Without reinforcement in these mounting areas, the repeated jolting upward pressures from the amas may detach the crossmembers.
Additionally, the '07's have a second "button" on the bottom of the hull to help secure the "V frame base" that distributes stress from the mast receiver assembly. Your '06 doesn't have this.
By the time you buy the AI kit and risk breaking your Adventure, I think you'd be money ahead selling the Adventure and buying an AI complete! Shop around.