Don are you stock height?I used 3/4" heavy duty weather stripping on the back of the horn and mounted it tight against the radiator using a modified stock bracket in the stock location. The foam compressed w/no damage to the radiator. It leaves plenty of room betweeen the horn and the fender.
Has anyone noticed that when it is cold, one of the horns doesn't work very well. As long as it is warm no prob, but when it is cold you only get half the sound.
Don
And I have noticed that is acts up in the cold too.