Ford FE 390 427 428 Internal Balanced Fluid Damper Harmonic Balancer SFI 18.1 and highly viscous silicone fluid

and highly viscous silicone fluid between the two--these SFI-approved Fluid dampers can control all crankshaft vibration

parallel-ground washers and high-strength 12-point heads

heat-treated to the highest Rockwell hardness available

They feature lightweight construction with a thick rail for gasket support

Speedmaster has already done the work for you

Ford FE 390 427 428 Internal Balanced Fluid Damper Harmonic Balancer SFI 18.1 and highly viscous silicone fluidUsing only three parts a laser welded sealed housing, an internal inertia ring, and highly viscous silicone fluid between the two these SFI approved Fluid dampers can control all crankshaft vibration, not just a limited frequency range. As a result, you get reduced wear on the main bearings and timing gear, more stable valvetrain operation, and less chance of crank failure.