WARNING: Mods to the head are your best shot at completely screwing up the motor.

It's also the first, and most important, step to improving performance. The trick is that it has to be done just right. The local shop that gets great results modifying Chevy heads is more likely to do good-looking damage than improve performance. Porting is completely non-intuitive -- you need someone with B20-specific experience and verifiable results.

See www.v-performance.com for a good overview and representative prices. Navigate to Products, then Engines and Related.