The Last Mopar Big Block Engine: The 400 V8

The Chrysler Corporation manufactured the last of its big block engines, the B-coded 400-cubic-inch V8, in the summer of 1978. The 400's disappearance ended a long run of Chrysler B-code engines that began in the late 1950s as 350- and 361-cubic-inch offerings. While the 400 V8 didn't possess the horsepower of the 426 Hemi or 440 Super Commando engines, it cost less to manufacture, weighed less, and fit into smaller engine bays.

Introduced in 1972, the Chrysler 400 V8 featured wedge-shaped cylinder heads, a single camshaft, and a pushrod-operated valvetrain. With a relatively low 8.2:1 compression ratio, the final 400 V8 version produced a mere 195 horsepower and 305 lb-ft of torque. Earlier takes on the same design delivered more performance in a smaller package.

If the engine had lost some sheer power, however, it had improved in quality. The 400 was a modern design with high-quality internal components. Some highlights include roller timing chains, chrome moly piston rings, and high-quality main and rod bearings. The 400 big-block V8 was bulletproof, but smaller, lighter engines eventually outperformed it, leading to its dismissal.

Several popular vehicles used the big block 400-cubic-inch V8. The engine was standard equipment as late as 1978 for larger cars like the Chrysler New Yorker and Newport. The engine also served as an option for Dodge D100 and D200 pickup trucks.

While earlier Newport and New Yorker models came with Chrysler's 440-cubic-inch big block V8 engines, consistent detuning and emissions controls finally led to it falling out of favor. By 1979, Chrysler's 400-cubic-inch big block engine was gone from the lineup, as the automaker adopted government-dictated Corporate Average Fuel Economy (CAFE) standards and emissions mandates.

The most common engines found in 1970s Dodge D-series pickup trucks are six-cylinder or small V8 varieties ranging from 170 to 360 cubic inches, producing up to 180 horsepower. While sufficient for various pickup truck-related chores, truck buyers with serious towing needs frequently opted for big-block power. The 400-cubic-inch V8 provided a middle ground compared to the big 440. Like its passenger car contemporaries, D-series truck engine options continued to shrink as smaller engines proved more efficient.