I had a Riffe Island that I had to put the wing kit on, but since sold it, I can't help with the dimensions. However, I can discuss tracking and other results.
Everyone seems to have a different meaning for tracking. The gun had been quite tip heavy before I put the wings on, and they really fixed that problem. I didn't have to strain my wrist to hold the tip up anymore, and the balance was much improved.
However, the wings made it much harder to move the tip vertically, as might be expected since they provide so much water resistance. I got in the habit of rolling the gun 90 degrees onto its side to move the tip up and down, and that is surprisingly easy to do.
My biggest objection to the wings is that when you were diving or ascending, you had to point the gun very precisely in the direction you were going. If the gun canted a few degrees off the direction in which it was going, then the wings would catch water and cause it to veer off course. That was quite annoying for me.
The bolt holes did not require sealing.
By the way, the wings did a good job of solving the problem that caused me to install them in the first place. The Island, like all the larger Riffe wood guns, is underweight and overpowered, particularly with the standard 5/16" shaft, so it recoils a lot and rotates around the resistance provided by your hand on the handle, causing the rising muzzle to push up the rear end of the shaft as it leaves, causing it to shoot low. I got tired of trying to figure how high above the fish to aim, so I installed the wings and they really did fix the problem. Whereas the gun had been inaccurate with just the standard three 5/8" x 28.5" bands without the wings, I was able to use a fourth band and remain accurate after I installed the wings. I did it just in time too, as I took it to Mexico and shot my first wahoo right after installing the wings.
