4.4, 13:1, custom aggressive cams and one off headers (e46 fitment) made 570/395 on the same dyno. Fatter curver and made power well past 8k.
A 600hp, 100 octane 4.4 is absolutely possible. These are all track cars, so they are running after market ECUs.
Sales Representative, VAC Motorsports
Office: 215.462.4666 | Fax: 215.462.4667 EXT 13 | Email: firstname.lastname@example.org