What gear ratio for a street car w/occasional track use?

High RPM's.

Don't count on getting a lot of passes at the NATS if you are doing fun runs. You may be better off to go to a local track before then to experiment with your launch RPM. Or find a deserted area somewhere to practice.

I've actually beaten some 440 powered cars with my street 318 because they were spinning and I was leaving just over idle.

I probably won't have a chance to make it to the track before the Nat's so I guess I'll just have to be happy with 1 run or maybe 2. Unless I do a late entry for the stick class :D