Ford 4.6L SFI Harmonic Balancer These two new dampers are designed for the 2005 and later 4.6L 3V Ford engine used in Mustang vehicles. If you are competitively racing your Mustang or using this engine in a race vehicle, then you need a damper that meeets SFI specification #18-1 and our Powerforce+Plus model is your most cost effective choice. Save over a hundred bucks compared to other dampers available for this engine.We also have the only low cost street style damper for the 4.6L 3V engine with our #80040 Powerforce model, recommended for heavy duty street applications on a modded Mustang. Performance heavy duty dampers provide extra insurance against a stock damper disintegrating at high engine speeds and causing major damage.