Engine - Harmonic Balancers - 8 inch Torsional Damper

From GM Performance - This 8 inch diameter torsional damper is designed for all internally balanced big block V8s. It was originally used on 1967-69 427ci engines. Technical Note: Use with crankshaft P/N 3967811 and chromed timing pointer P/N 12342001.

From GM Performance - An externally balanced 4.00 inch stroke crankshaft used in a 454 and 502ci big-block Chevrolet engine requires a counterweighted damper for proper engine balance. This harmonic balancer is used with LS-6 and LS-7 engine assemblies. Technical Note: Use with crankshafts P/N 3963523-4 and chromed timing pointer P/N 12342001.