The horn on my 54 gmc is mounted on the front driver side of the rad cradle .Don’t know if it is a 54 change or maybe a Canadian difference.I also seen some mounted on the passenger side firewall .I had to move mine to the inner fender from the rad cradle because of moving the rad and the mounting holes covered by the rad .The vibrations from the horn on the inner fender made the inner fender crack all around the horn mount so it needs some cushion to absorb the vibration.
