The AMC 401 cubic inch engine is one of the least-known American V8s of the muscle car era and one of the most underestimated.

AMC developed the 401 as a derivative of their corporate V8 in configurations from 290 to 401 cubic inches. The 401 four-barrel in the 1971-1974 AMX and Javelin produced 330 horsepower in an era when larger-displacement engines from other manufacturers were being detuned.

The AMC 401 responds to the same modifications as any other pushrod V8: better carburetion, free-flowing exhaust, mild cam advance. The potential is significant. The aftermarket support is thin compared to Chevrolet and Ford equivalents, but the AMC community has compensated with a deep knowledge base and creative solutions.