It does get confusing....Historically there was a falling out between the racers (now ARCA) and the AROC powers-that-were. Hopefully in the future that rift might be healed as personalities have changed......
First: there is the ARCA championship - pretty much anything can race but obviously in different classes, but it can get hairy with full-blown racers on slicks mixing it with "production-class" cars on List1A/1B tyres.
Then there is the CTCRC / AROC race series, which is in its first year - and which I have some peripheral involvement in - and hope to race in. This was originally intended as having the pre-79 RWD cars (they really only wanted 105 series or earlier cars) in one class, with other cars running in either "Classic Thunder" or the "Blue Oval" races, in an Alfa class. Full details here: http://www.aroc-uk.com/news/2012/alf...challenge-2012
Realistically the first race (at Silverstone) was not oversubscribed, and eligibility was widened to allow "invitation" cars including Alfetta GTV s and 75s to enter, and for the second race in the series (at Brands Hatch) the series ran with the same mix plus Suds, and was incorporated within the CTCRC Post-historics.....and an excellent race it was, too.
If anyone is interested in racing in the CTCRC / AROC series, either this year or next year, feel free to call me on 07976 384980 and I'll be happy to chat - I'm particularly interested in how we develop the Series for future years, as plans for this year are fixed in terms of events, but as has already happened - class structures can (and doubtless will) still be tweaked