You can run a turbo/sc on a stock engine, as long as it's properly tuned. I like the greddy kit as well. Most people don't like it because it makes slightly less power than kits with a bigger turbo. However, the smaller turbo will spool faster. The greddy kit also comes with everything you need, down to the last nut and bolt, and the quality is excellent. Greddy is the only CARB certified turbo kit as well.