According to your serial number and the style of the bike, this is a 1962. I have seen El Camino's from time to time, they are nice looking, good riding bikes.
Saving Tempest is correct. Huffman Corp. bought out Monark in 1958 for the extra manufacturing capacity. The Monark name was marketed in small, lesser-known, catalog order department stores, not so much traditional brick and mortar stores like J.C. Penny or Sears. If they were, I have yet to see literature proving it. Best I can figure, the Huffy brand was sold through sporting goods stores and bicycle shops. The Monark brand was used for catalog department stores. It protected the Huffy brand name equity, yet gave Huffman Corp an edge on market share. It worked for a short time. Monark literature from this period is hard to find, I have to go off what little info I dig up.
The Monark bikes were nearly identical to their Huffy counterparts. It got so bad, that by the mid '60's, you had Huffy and Monark badges or logos or trim on the wrong model. From the factory. Saving Tempest has a Monark Thunderbird, with a Huffy chaingaurd. I know because I was the one who parted it out and the previous owner still has the tank.
Your bike is completely correct. Below is my 1961 Monark Spartan and 1964 Monark Silver King: