Hotrod Lincoln is right, I worked for a race shop in N.Georgia for over 15 years that built some of the most awesome inline Chevy 6 cylinder drag engines ever. We also built most of the engines for the areas Southern All Stars dirt racers as well as many other series. And one thing I learned is that even with some class restrictions in those dirt classes limiting you to cast iron heads, the GM Vortech and Bowtie cast iron heads still easily would achieve 500+ HP without porting or a lot of expense.
