W2W = shorthand for Wheel to Wheel racing. ie, not rally, time trials, hill climb, autocross or track time.
SPO does not have a national title championship/points, ergo it is 'regional.' You probably want to look at the GCR. The SCCA has announced they will be revising the website (again). I find searching best using an outside search engine. As Tony mentioned, its SCCA's fairly recent attempt to keep drivers with cars no longer classified.
Northeast and Mid-atlantic Vintage racing clubs:
HRG = Historic Racing Group.
http://historicracinggroup.com/SVRA and HSR rules touched on here
http://www.forabodiesonly.com/mopar/showpost.php?p=1970082938&postcount=25I'm pretty sure you'll need an SCCA racing drivers license for any of these clubs. So add that into your time and dollar budgets.
