Cliff,
If you are looking for a low-key group to race with in the Northwest, I'd recommend the International Conference of Sports Car Clubs (ICSCC, aka "Conference"). Conference puts on races at Seattle, Portland, Spokane, British Columbia, and sometimes other places like Thunderhill. I've been racing with conference for 17 years. They are a good group. The safety rules are fairly strict--similar to SCCA, but the atmosphere is more relaxed, and the races are more efficiently run than the local SCCA races. SCCA classes are recognized at Conference events (I race in ITA--International Touring A--a low-buck production car class with lots of close competition) and there are some conference-specific classes as sell. Like Ron says, a GT40 kit is probably most appropriate for SPO. If I was building a car that I wanted to race, however, I'd take a look at the rules for GT1. GT is more restrictive than the SP classes, but you might have more opportunities to race in multiple groups.
Speaking about racing in general...unless you have experience with real racing (NOT track days) I would recommend getting a taste for it before committing a GT40 build to race car rules. One of the best ways is to buy a cheap production-based race car and run the Conference novice program. You'll pay less for the car and the racing than it would cost to modify a GT40 for racing, and you'll gain more driving skill more safely in a low-powered car. And you can sell the car when you are done.
If all you want to do is take the GT40 on the track and fart around, a track day is a better choice, and there are basically no rules. It isn't a racing experience however, and there are all skill levels at track days. (Read: "The more car than skill crowd sometimes shows up.")
Personaly, my ERA will not be set up as a race car, and I plan to continue to race my Corolla GT-S. This is because racing a car competitively basically means that you must be willing to destroy the car. Bad stuff can and does happen. I'd rather that happend in a relatively slow, cheap car.
Some guys don't have the ego to race a small car, but there is more competition and fewer mechanical problems in the smaller production car classes. In my last race, there were 5 cars entered in SPO, 4 didn't start the race, the lone starter didn't finish. GT1 had 7 starters, 3 finishers, and a 4th finisher that was DQ'd. ITA, however, had 21 starters and 20 finishers. I finished 6th, and the guy that finished second had a fastest lap only 0.34 seconds faster than me. The cars in SP are really cool, but the racing is much better in IT.
ICSCC:
International Conference of Sports Car Clubs
ICSCC Portland Race Results:
http://www.icscc.com/results/sept24_06/Sept24_2006_Race.pdf
Garrett
