6.5 Inch Ford Y-Block Harmonic Balancer Internal Balance with Thunderbird Length Hub

6.75″ 455″ Oldsmobile Harmonic Balancer #501

$535.00 – $605.00

The dampers for the Oldsmobile 455 engines feature an OEM 4-bolt pulley pattern and male pulley register. The dampers have OEM offset. The #501 damper is designed for use with the OEM external balanced crankshaft. The damper may be used with an internal balance crankshaft by removal of the bolted on counter weight.

  • Outer Diameter: 6.75″
  • Weight: 7.4 lbs
  • Exceeds SFI 18.1 standards and is marked on front with SFI Sticker, and on the rear with SFI number stamped into unit.

Double 1/4" Keyway Add On

Dual  1/4" Keyways (Requires a Blower/Super Duty Hub or BBC Crank Snout) Required the crankshaft to be machined for a second keyway 180* out from the original keyway. *Requires damper purchase. This is a labor option for new damper purchase only.

SKU: 501 Category:
Damper Installation Instructions [PDF Format].
Damper Hub Honing Instructions [PDF Format].
Harmonic Damper Installation YouTube Video