Stanley R. Harris had a long career as a publisher. He began working in the field in the 1960s and started his own firm in 1977. He printed automotive, beauty, craft, guns and entertainment magazines - just to name a few. But the organization was best known for comic books. Harris Publications ended in 2016 with its sale to Athlon Media.
Titles in the automotive category were small in comparison to other genres. Harris worked with Myron Fass in the late 1970s to jointly publish Vette Power under Harris' Modern Day Periodicals Inc. organization. This is likely how Mr. Harris learned about the automotive publishing realm. You can see the similarity in the use of limited runs to test the feasibility of new titles.
The various one-shots featured below appear to be Harris' first attempt to launch automotive titles after a string of successes in other categories. These titles were attempts to find a new market or niche. None seemed to gain much traction to become full fledged recurring titles, and it was 1988 before an automotive title really took off - Mopar Action.