Dodge 440 Engine for Sale | OEM RB Big Block V8 (Magnum and Six Pack)

Description

Engine Background

The Dodge 440 is one of the most iconic American muscle car engines ever built. Introduced in 1966 as the successor to the 426 Max Wedge, the 440 is a 440 cubic inch RB (Raised Block) big block V8 that Chrysler chose to build around maximum torque rather than maximum rpm. With a 4.320-inch bore and 3.750-inch stroke (oversquare dimensions that favor breathing over low-end grunt), the 440 produced 375 hp and 480 lb-ft of torque in Magnum form, making it one of the most torque-rich engines available in any American car of its era. Chrysler’s philosophy was that torque wins real-world races while horsepower wins dyno comparisons.

The 440 Six Pack, introduced in 1969, took the engine to its performance peak. Three dual-throat Holley 2-barrel carburetors (hence Six Pack and Six Barrel) gave the 440 an enormous fuel delivery advantage under wide-open throttle, pushing output to 390 hp and 490 lb-ft of torque. The center carb handled everyday driving; the two outboard carbs only opened under hard acceleration. This gave the Six Pack reasonable fuel economy during normal driving while delivering brutal performance when needed. The Six Pack powered the Dodge Super Bee, Dodge Challenger, Plymouth Road Runner, Plymouth Cuda, and Plymouth Sport Fury GT.

The 440 powered virtually every significant Dodge and Plymouth muscle car: the Charger R/T, Coronet R/T, Super Bee, Challenger R/T, Road Runner, GTX, and Fury GT among others. It remained in production through 1978, though high-compression performance versions ended after 1971 due to tightening emissions regulations. Call (240) 306-7051 to confirm variant and casting availability.

When Replacement Becomes Necessary

• Knock under load, rod or main bearing wear on high-mileage RB engines
• Blue smoke on startup, valve stem seal deterioration on aged 440 cylinder heads
• Loss of compression on one or more cylinders, ring wear or scored cylinder walls
• Oil leaks at timing cover and valve covers, common on aged Mopar big blocks
• Rough idle or carburetor stumble, accelerator pump failure or float level issues on aged Holleys
• Low oil pressure at idle after warmup, bearing clearance wear on high-mileage engines

Known Issues We Document Before Shipping

• Head casting compatibility: the standard 440 and the Six Pack used different cylinder head castings. Standard 440 Magnum heads and Six Pack heads use different intake manifold bolt patterns in some configurations. We document the head casting number for every unit before shipping.
• Casting number significance for restoration buyers: for show-quality Mopar restorations, the correct casting number matching the vehicle’s production date code is critical to authenticity and value. We document and disclose the block casting number, head casting numbers, and date codes for every unit.
• High-compression emissions incompatibility: pre-1972 high-compression 440s (9.7:1 to 10.3:1) require premium leaded fuel or a valve seat hardening conversion for use with modern unleaded fuel on extended highway runs. We note compression ratio for every unit.
• Emissions-era detuning: post-1972 440s were progressively detuned for emissions compliance. By 1975 a low-compression 440 produced 275 hp versus the 1969 Six Pack’s 390 hp. Year matters significantly for restoration buyers seeking specific output levels.
• Six Pack carburetor sourcing: the original Six Pack used three specific Holley carburetors with progressive linkage. Original Six Pack carbs are increasingly rare. Aftermarket Six Pack reproductions are available from Mopar specialists but require careful selection for show-quality restorations.

440 Variants by Year and Application

Critical buyer information across the 1966 to 1978 production run:

What Ships and What Does Not

Direct-Fit Vehicle Applications

Search Terms Buyers Use

Not sure which 440 variant matches your project? Call us at (240) 306-7051. We verify casting number, variant, and year before every order ships.

Used OEM Versus Specialist Rebuild

For a Charger R/T, Challenger R/T, Road Runner, Super Bee, GTX, or other 440-equipped Mopar restoration on a reasonable budget, a documented used 440 with casting number verified and compression results uniform is the cost-effective path. For a show-quality restoration with judging or a high-performance build targeting over 500 hp, a specialist rebuild with refreshed heads, refreshed crankshaft, and supporting hardware is the better investment. Specialist 440 rebuilds typically run $8,500 to $16,000 from established Mopar big block shops. Six Pack-equipped builds add cost for carburetor restoration.

Inspection Workflow

• Compression test logged across all 8 cylinders with uniformity reported
• Block casting number and date code documented
• Head casting numbers and date codes recorded
• Variant identified: standard, Magnum, Six Pack, or HP
• Year confirmed: 1966 to 1971 high-compression, 1972 to 1978 emissions-era detuned
• Six Pack versus single 4V intake configuration verified
• Main cap configuration: 2-bolt standard or 4-bolt (Six Pack and high-output variants)
• External oil leak survey at timing cover, valve covers, oil pan

Pre-Purchase Buyer Notes

• Match year to your build target: a 1969 Six Pack produces 390 hp; a 1975 emissions-era 440 produces 275 hp. The architecture is similar but state of tune is dramatically different. Match year to your target output and authenticity needs.
• Confirm casting number for restorations: show-quality Mopar restorations require correct casting numbers matching the vehicle’s production date. Casting numbers and date codes are documented on every unit we sell.
• Plan for premium fuel or valve seat conversion on high-compression units: pre-1972 high-compression 440s (10:1+) need either premium fuel or a hardening conversion of the valve seats for extended modern-fuel operation.
• Source Six Pack carburetors carefully: original Holley Six Pack carburetors are increasingly rare and command premium prices. Aftermarket reproductions are available; specify quality level when ordering Six Pack-related work.
• Use ZDDP additive: all 440s use flat-tappet camshafts (the architecture predates roller cams in this engine family). Modern low-zinc oils accelerate cam lobe wear. ZDDP additive is essential.

Why Buy From Part Nests

• Block and head casting numbers documented before payment
• Variant confirmed: standard, Magnum, Six Pack, or HP
• Year identified for high-compression versus emissions-era distinction
• Main cap configuration noted: 2-bolt or 4-bolt
• All 8 cylinders compression-tested with uniformity reported
• No core return required
• Free freight delivery to every state
• 15 day replacement warranty against internal defects
• Call (240) 306-7051 to speak with someone who knows Six Pack identification, casting number significance for Mopar restoration, and high-compression versus emissions-era 440 differences