Mercury – Valve Spring Kit | 357 CT Iron Heads | Precision Steel Components | 8M0120862Mercury Valve Spring Kit 357 CT Iron Heads Precision Steel Components 8M0120862 Overview Anyone whos spent time around a circle track engine knows theres a rhythm to performancean even, confident pulse that tells you the valvetrain is working exactly as it should. When that rhythm slips, even just a little, you feel it right away. Thats why replacing worn components with trusted parts matters so much. The Quicksilver 8M0120862 Valve Spring Kit brings