This steel crank hub and pulley will fit standard dimension harmonic balancers on Holden red, blue and black motors when fitting a supercharger and using the other components in the Aussiespeed Holden 6 supercharger kit. The outer ring or 120mm diameter extends past the outer v belt ring to stop the dampener from sliding forward.
This can only be used with flat faced harmonic balancers, it will not fit after market non standard dimension balancers like Romac, Powerbond without additional spacers.
The Harmonic balancer you use will need to have a step machined into the centre to locate the hub. This can be done by most machine shops for a minimal cost.
We can supply a balancer with this step already machined. They are listed in the Holden 6 section of our website.
The dampner on the left is red motor, the right is for blue and black as it has the thicker back edge and a different timing mark.