Ah yes, GM "A" bodies had front control arms, upper and lower, and the 4 link coil spring suspension in the rear had upper and lower control arms.
The higher performance models (SS, 442, GTO, etc.) had the rear lower control arms "boxed" to reduce deflection on hard launch, and to make it possible to mount a rear anti-sway bar. These are available through some of the specialty restoration parts businesses. The after market is full of tubular, high strength, redesigned, and all sorts of performance suspension and braking components for these cars.