Harmonic balancer 340
This is the best picture I could take, had to hold a flashlight in one hand and the camera in the other.
Picture is of a 1972 340 cast crank, factory balancer and timing cover.
The measurement is 2.4" from the timing chain cover to the back side of the balancer.
![](http://imagizer.imageshack.us/v2/640x480q90/903/hF9M0y.jpg)