L75 / passenger-car 327
1960sApplication-dependent
Brought 327 power to a broad range of Chevrolets.
Chevy 327 enginePhoto: Valder137 · CC BY 2.0
Chevrolet · Small-Block Chevrolet
Chevy 327
One of the classic high-performance small-blocks
327
Cubic inches
The 327 combined a 4.00-inch bore with a relatively short 3.25-inch stroke, giving Chevrolet a responsive small-block that could make excellent high-rpm power without giving up everyday drivability.
Key variants
All variantsL75 / passenger-car 327L79 327High-output Corvette 327
Displacement
327 ci
Bore
4"
Stroke
3.25"
Years
1962–1969
Key Takeaway
The 327 combined a 4.00-inch bore with a 3.25-inch stroke, giving it strong breathing potential and a quick-revving character that made it a favorite before the 350 took over the mainstream performance role.
Technical Specifications
- Compression
- Varied by application, including high-compression performance versions
- Horsepower
- Multiple ratings from everyday versions to 350+ hp gross performance combinations
- Torque
- Varied by application
- Architecture
- 90° OHV V8 · Gen I Chevrolet small-block
- Block
- Cast iron
- Cylinder heads
- Cast iron in factory production versions
- Valvetrain
- Pushrod OHV · 2 valves per cylinder
- Aspiration
- Naturally aspirated
- Fuel delivery
- Carbureted; mechanical fuel injection on select Corvette applications
- Firing order
- 1-8-4-3-6-5-7-2
- Main bearings
- 5
The 327 combined a 4.00-inch bore with a 3.25-inch stroke, giving it strong breathing potential and a quick-revving character that made it a favorite before the 350 took over the mainstream performance role.
Internal Specifications
Variant-specific values are labeled. Engine families that span multiple years or RPOs can have different heads, cams, induction and rotating parts, so the exact code/year always takes priority.
Identification & Output
- Engine codes / RPO
- L75, L79
- Casting numbers
- 3782461 (1964–66 L79-era camel-hump head reference), 3890462 (later 1966–67 high-performance head reference)
- Power rating
- SAE gross (period factory ratings)
- Horsepower RPM
- 350 hp @ 5800 rpm (L79 high-performance reference)
- Torque RPM
- 360 lb-ft @ 3600 rpm (L79)
Rotating Assembly
- Crankshaft
- Forged steel crankshaft in L79 high-performance applications
- Rod length
- 5.70 in
- Pistons
- Forged domed aluminum pistons in L79 high-performance applications
- Piston pin
- 0.927 in nominal small-block pin diameter
- Balance
- Internally balanced
- Rear main seal
- 2-piece rear main seal
- Deck height
- 9.025 in nominal Gen I small-block deck height
- Main journal
- 1962–67: 2.30 in · 1968–69: 2.45 in
- Rod journal
- 1962–67: 2.00 in · 1968–69: 2.10 in
Cylinder Heads
- Chamber
- About 64 cc on factory big-valve L79-style camel-hump heads after intake-valve unshrouding
- Intake valve
- 2.02 in (L79 high-performance head)
- Exhaust valve
- 1.60 in (L79 high-performance head)
- Intake runner
- About 160 cc on 3782461 camel-hump head reference
Cam & Valvetrain
- Camshaft
- High-performance hydraulic cam · Chevrolet P/N 3863151 associated with L79
- Cam lift
- 0.447 / 0.447 in intake/exhaust (L79)
- Duration @ .050
- 221° / 221° intake/exhaust (L79 reference)
- LSA
- 114° LSA (L79 reference)
- Rocker ratio
- 1.50:1
Operating Specs
- Redline / max RPM
- Performance instrumentation varied by application; verify model/year rather than using a single 327-family redline
- Fuel / octane
- Special premium fuel specified for L79 high-performance Corvette applications
- Oil capacity
- 1965 Corvette L79: 5 qt refill / 6 qt with filter
- Induction
- Four-barrel carburetion on aluminum high-rise/dual-plane intake in L79 performance applications
- Oil pan / sump
- Corvette L79 applications used a special larger baffled oil pan; other L79 vehicle applications differed
- Production notes
- The 327 family covered many applications; the builder specs on this page use the L79 as the high-performance reference. In 1966, Chevrolet produced 7,591 Corvettes with RPO L79, rated at 350 hp.
Service Specs
- Spark plug
- AC 44 (1965 Corvette 327 reference)
- Spark-plug gap
- 0.033–0.038 in factory range
- Ignition timing
- 10° BTDC @ 650 rpm for the 1965 Corvette L79
- Valve lash
- Hydraulic lifters · zero lash / preload procedure on the L79
- Oil pressure
- 30–45 psi @ 1500 rpm (1965 Corvette factory specification)
- Fuel pressure
- Mechanical carburetor fuel-pump system; use the exact vehicle/year service specification for pressure
Compatibility Notes
- Small-journal and large-journal 327 variants exist; verify the exact block and crankshaft before ordering rotating components.
- Period high-compression combinations may require modern fuel and ignition planning if restored to original specifications.
Notable Applications
CorvetteChevelleNovaCamaroFull-size Chevrolet models
Strengths
- Strong revving character
- 4.00-inch bore supports good cylinder-head airflow
- Excellent performance heritage
Weaknesses / Watch-outs
- Original high-performance components can be costly
- Less low-rpm torque than larger stroked SBCs
Common Upgrades
- Performance cylinder heads
- Camshaft and valvetrain
- High-rise intake
- Headers
Racing History & Legacy
High-output 327s became fixtures in Corvette, drag-racing and street-performance circles throughout the 1960s.
A favorite among enthusiasts who want classic small-block response and period-correct performance.
References & Image Credit
Engine image: Valder137 · CC BY 2.0 · source
GM Heritage Archive vehicle information kits
manufacturer archive
Wikimedia Commons 1968 Camaro 327 engine image
licensed media
1965 Corvette factory AMA specifications
manufacturer specification
1965 Corvette L79 specifications
historical specification
Corvette Action Center — 1966 Corvette L79 production
historical specification
Key Factory / Build Variants
L79 327
1960s350 hp gross in well-known applications
A famous hydraulic-cam street-performance combination.
High-output Corvette 327
1960sMultiple high-performance carbureted and fuel-injected ratings
Established the 327 as one of Chevrolet's premier small-block performance engines.
Engineering Notes Worth Knowing
01
The 4.00-inch bore supports strong cylinder-head airflow and many later SBC head choices.
02
Its shorter 3.25-inch stroke gives a different powerband than the later 350's 3.48-inch stroke.
03
Period-correct high-compression and solid-lifter versions require fuel and maintenance appropriate to their original design.
History · context · related reading
The Story Behind Chevy 327
For many enthusiasts, the 327 is the sweet spot of the early small-block family. It kept the 4.00-inch bore racers wanted but used a shorter stroke than the 350, giving it a reputation for crisp response and high-rpm power.
Performance era
01Why the 327 became a high-rpm favorite
How its bore-and-stroke combination helped define the feel of Chevrolet performance before the 350 became dominant.
Factory legend
02The L79 formula: street manners with real power
Why the hydraulic-cam L79 became one of the most respected street-performance 327 combinations of the 1960s.
Comparison
03327 vs 350: same bore, different personality
How adding stroke changes torque, rpm behavior and the way two closely related small-blocks feel on the street.
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