The short part of the story, and there are many here who can verify, or even tell it better, but who cares, I know I'll get most of it right, was that soon after the inception of the A/FX class, they , within a few years, were outdated, as the '66, '67 started to see the rise of the flopper style flip top. There were so many of these cars still in circulation all across the country, that many privateers, who still owned them, needed venues. So, race track owners would stage weekend shows, and attempt to get as many of these cars into the staging lanes as possible, as the crowds were still itching to see the match-ups. Hence the term , match bash, or match race. Remember that back then, regular working class guys were campaigning these cars, to help make money, more like a side gig. Some did very well.
Dale