Got one installed by John Sachs on my S&S Super G.
Love it.
As for what you can expect from one bike over another, couldn't tell ya.
What results did you get on the HD?
What other mods have you done to the Boxer?
Pipes, cam, AC all that stuff matters.
What works on one bike may not be as great a mod on another.
You should send John a PM and give him the details about your dog and see what he recommends.:up: