Nearly all new cars have control arms for the front suspension system, not the rear suspension. This is primarily due to the fact that only the front wheels are controlled by the steering wheel.
The Arizona Z Car control arms (which fit all Datsun 240Z 260z & 280Z) have spherical bearings at the pivot points for zero play or deflection in the suspension under load and low friction, free movement of the arms unlike control arms with urethane bushings. The threaded inboard ends also add camber and toe adjustment to the rear suspension to dial everything in precisely. This is a big step forward as the stock Datsun 240Z had no suspension adjustments available in the rear from the factory.