I can highly recommend you fitting one of these horns.
DENALI SOUND BOMB
I know they are expensive but well worth the money for peace of mind letting the idiot drivers know you're there. I also got the plug and play wiring kit which makes it a doddle with wiring it all up.
It's a bit of a tight squeeze fitting the compressor somewhere out of the way. The horn part will fit the original horn bracket but I had to bend my bracket downwards so the horn unit didn't come into contact with anything. It took me quite a while to get to get it all installed but it puts a big smile on your face when you first press the button for the first time.
Denali sound bomb split.
Denali sound bomb split.
Bit of advice. Buy a good bed and a good pair of shoes, because if you aren't in one you'll be in the other.