JCWhitney does have a couple of different versions. One is designed to be used as a replacement for your current horn.
It's $44.99. Their catalog #WK812716. I think you need the installation kit for this one, $7.99, catalog #WK888315.
They also have the one described by 56picup. $79.99, catalog #WK142568.
If you have a catalog, they're on page #140.
By the way, both horns are 12 volt electric.
