What's the difference between the Dodge 440 and 426 Hemi?

The 440 and 426 Hemi are both Chrysler B/RB-series big blocks sharing external dimensions but with entirely different combustion chamber geometry. Understanding the difference is essential for any buyer of 1966–1974 Dodge or Plymouth performance cars.

The 440 — The Practical Performer

The 440 cubic inch (7.2L) uses a conventional wedge combustion chamber design. Available in three primary performance configurations:

• 440 Magnum (375 hp): Single four-barrel Carter AFB or Holley. The standard high-performance 440 in Charger R/T, Road Runner, Super Bee.
• 440 Six Pack (390 hp): Three Holley two-barrel carburetors on an Edelbrock-designed intake manifold. Factory-installed on select 1969–1971 models. More torque than the single four-barrel, more tractable than the Hemi.
• 440+6 (street Six Pack): The definitive street Mopar engine — abundant torque, reliable, parts available everywhere. Most consider it the best driving big block Mopar engine.

The 426 Hemi — The Racing Engine

The Hemi uses semi-hemispherical combustion chambers — the dome shape that gives the engine its name. The geometry allows larger, more efficiently positioned valves and a more complete combustion event than a wedge head. Factory ratings were 425 hp at 5,000 rpm and 490 lb-ft torque, but period dyno tests consistently showed actual output closer to 500–520 hp.

The Hemi came with dual four-barrel carburetors on a cross-ram intake manifold. It requires premium fuel, more frequent valve adjustments, and specific Hemi-only components throughout the top end. A Hemi engine rebuild at a Mopar specialist runs $8,000–$15,000 — roughly double the cost of a 440 rebuild.

The Value Difference

In a 1969 Dodge Charger R/T: a documented 440 car trades at $55,000–$90,000. A documented Hemi car trades at $120,000–$200,000. The Hemi premium is real, substantial, and has been widening since 2015. Authentication (fender tag E87 code + block stamp) is the only way to confirm factory Hemi installation.