===== Harmonic Balancer Information =====
Because of the different years and engines, there were four different harmonic balancers used on the Z31's VG30 engines. Below is a chart to help determine which one you want to use.

^  Year  ^  Engine  ^  Aspiration  ^  Part Number  ^  PS Pulley  ^  AC Pulley  ^  H2O/Alt Pulley  ^
|  1984-1986  |  A/B Series  |  non-turbo  |  12303-V5020  |  V-Belt  |  V-Belt  |  V-Belt  |
|  1984-1986  |  A/B Series  |  turbo  |  12303-V5320  |  V-Belt  |  V-Belt  |  micro-V  |
|  1987  |  A/B Series  |  all  |  12303-F6100  |  micro-V  |  micro-V  |  micro-V  |
|  1987-1989  |  W Series  |  all  |  12303-21V10  |  micro-V  |  micro-V  |  micro-V  |


You can use the A/B series balancers on the W series crankshafts if you get the spacer from Nissan (p/n 12308-V5321).

You should be able to use a W series balancer on an A/B series crankshaft if you get a slightly longer bolt with matching threads.