A friend gave me a copy of his "Super Chevy" November 05 issue yesterday. In it there are three articles, that as a novice to this performance game, I found informative. The article I found to be most helpful, was on performance exhaust basics (not only Chevrolet), which immediately allowed me to follow the header diameter discussion this morning. I've said it to JMatt in an earlier post. I really thank you guys that are fearless and experiment with your cars. It gives guys like me that are very new to this game and a lot more tentative / conservative, opportunities to make more comfortable decisions.