“The Z 423 was a Japan-only version of the Fairlady Z equipped with the same 2.0-liter inline-six S20 engine producing 160-horsepower and 177Nm as the Skyline GT-R (PGC10). It was built in limited number of units for homologation purposes. The name ‘432’ refers to the 4 valves [per cylinder], 3 carburetors and 2 camshafts.
Along with the GT-R’s straight-six that was coupled to a five-speed manual gearbox, the Z 432 featured many other upgrades including Magnesium wheels and a unique exhaust system with dual vertical tail pipes“
via JDM Chicago