Turbo 6.1 Demon

Stage 6 guy told me on Facebook that they were building a forged engine for that car and hope to get 800-850 whp on 93 octane.

Keep in mind that the 600 whp was on a bone stock 6.1 with only 8.5 lbs of boost. That's about the max boost level most guys are comfortable with on stock pistons.