The U-code 440 uses the same RB block as the V-code Six-Pack but with a single Carter Thermo-Quad four-barrel carburetor on a cast-iron intake. Period rating: 375 horsepower gross at 4,600 rpm, 480 lb-ft of torque at 3,200 rpm. It was Dodge's 'Magnum 440' and Plymouth's 'Super Commando 440'.
Compared to the Six-Pack, the U-code is a calmer, more torque-rich engine; quicker off-idle, less peaky at the top end. It was the standard big-block on cars where the Six-Pack and Hemi were optional, and it's the engine most owners drove daily.
