6.9" Pontiac V8 326/350/389/400/421/428/455 1961-79 Harmonic Damper

Our 80020 damper is the dimensional duplicate of the O.E. damper used on the 2V engine. If used on a 4V engine, the accessories (alternator, A/C, etc) will rotate 3% slower than stock. Normally this is not a significant amount. This is due to a slightly different diameter of the damper. These dampers do not have timing marks on them but do have a notch in the back rim of the damper indicating TDC