(passenger side, I think) I had to move it a couple of inches. There are plenty of mounting holes under there so it's not an issue.
Used the existing connectors, no new wiring block, and ran a separate ground wire from each horn to the body nearby. For some strange reason the very detailed instructions that came with them try to get you to run a common ground wire connecting the two horns. Unnecessary, and I don't have a wire going all the across my front fascia the way I did it.