You can find the 2011 NorCal calendar here: http://www.nasanorcal.com/
I don't believe there are any conflicts with the San Francisco Region SCCA events this year. So, you don't have to make a choice between organizations, you can run both!

I also want to make sure that you are aware of some important rule changes for the 2011 season across the model years.
First and perhaps most dramatically, NASA has changed the minimum weights and restrictor plate sizes in an effort to bring the performance of the different model years closer together. The wisdom of these changes, which represent a significant departure from the approach the SCCA is taking, has been debated almost to death in this forum, so I'd rather this NOT become another thread about that.

Other rule changes for 2011 in the NASA Spec Miata Series.
11.2 "Balancing of Crankshaft and Flywheel is permitted; minimum weights listed in these rules must be maintained."
11.3.3 will allow tape or insulating foam to replace Radiator Seal Plate
12.5.3 For 1999-2005 it is permitted to alter the ignition timing by elongating the mounting holes of the crankshaft position sensor trigger wheel
12.9 Fuel Pressure - Any adjustable mechanical fuel regulator may be used, but it may not be adjustable from the cockpit
13.2: Allowing both the 4.1 and the 99+ upgrade 4.3 but the 4.3 is mandated for the Nationals.
14.1: Front 27mm non-Adjustable or adjustable 24mm front bar ... may be used. However, the 24mm must be used for the duration of the NASA Nationals event.
14.7 1990-97 cars are permitted to use the “R†model tie rod ends part # N021-32-280A
15: Steering rack - allowing shimming (0.5" max) between the rack & subframe.
The first event of the year is February 12th-13th at Infineon. I hope to see many of you that weekend or at another NASA event this year. If you have any questions, please don't hesitate to contact me directly. It's my job to make it easy for you to attend and enjoy NASA events.
Cheers,
Dean Thomas