1967 Z/28 302
1967290 hp gross advertised
The first Camaro Z/28 engine, created around Trans-Am displacement rules.
Chevy 302 enginePhoto: BUTTON74 · CC BY-SA 4.0
Chevrolet · Small-Block Chevrolet
Chevy 302
Built to rev and built to race
302
Cubic inches
Chevrolet combined a 4.00-inch bore with a short 3.00-inch stroke to create a high-rpm 302 specifically suited to Trans-Am-era displacement rules.
Key variants
All variants1967 Z/28 3021968 Z/28 302DZ 302
Displacement
302 ci
Bore
4"
Stroke
3"
Years
1967–1969
Key Takeaway
The 302 combined a 4.00-inch bore with a 3.00-inch stroke to fit Trans-Am's 5.0-liter class limit while preserving strong cylinder-head breathing and high-rpm capability.
Technical Specifications
- Compression
- High-performance ratios varied by year
- Horsepower
- 290 hp gross advertised in Z/28 applications
- Torque
- 290 lb-ft gross advertised in common Z/28 ratings
- Architecture
- 90° OHV V8 · Gen I Chevrolet small-block
- Block
- Cast iron
- Cylinder heads
- Cast iron in factory Z/28 applications
- Valvetrain
- Pushrod OHV · 2 valves per cylinder · solid-lifter performance valvetrain in key factory versions
- Aspiration
- Naturally aspirated
- Fuel delivery
- High-performance carburetion; cross-ram systems were used in competition-oriented setups
- Firing order
- 1-8-4-3-6-5-7-2
- Main bearings
- 5
The 302 combined a 4.00-inch bore with a 3.00-inch stroke to fit Trans-Am's 5.0-liter class limit while preserving strong cylinder-head breathing and high-rpm capability.
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
- DZ (only 1969 302 engine suffix)
- Casting numbers
- 3927186 (1969 Z/28 production cylinder head)
- Power rating
- SAE gross (period factory ratings)
- Horsepower RPM
- 290 hp @ 5800 rpm (advertised 1969 Z/28)
- Torque RPM
- 290 lb-ft @ 4200 rpm (1969 Z/28)
Rotating Assembly
- Crankshaft
- Forged steel high-performance crankshaft
- Connecting rods
- Selected forged/shot-peened high-performance connecting rods
- Rod length
- 5.70 in
- Pistons
- Forged aluminum domed pistons · 11.0:1 factory Z/28 compression
- 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
- 1967: 2.30 in · 1968–69: 2.45 in
- Rod journal
- 1967: 2.00 in · 1968–69: 2.10 in
Cylinder Heads
- Chamber
- 63.305 cc (1969 Z/28 3927186 production head)
- Intake valve
- 2.02 in
- Exhaust valve
- 1.60 in
Cam & Valvetrain
- Camshaft
- Mechanical solid-lifter “30-30” cam · Chevrolet P/N 3849346
- Cam lift
- 0.485 / 0.485 in intake/exhaust
- Duration @ .050
- 254° / 254° intake/exhaust for GM 3849346 “30-30” profile
- LSA
- 114° for GM 3849346 profile
- Rocker ratio
- 1.50:1
Operating Specs
- Redline / max RPM
- 1969 Z/28 factory tach markings varied by build period: early cars used a 7000-rpm redline tach; later cars received 8000-rpm tachs with revised yellow/red zones
- Fuel / octane
- Premium gasoline specified for the 302 Z/28
- Oil capacity
- 5 qt total with filter in the 1969 Camaro owner's-manual specification
- Induction
- Holley 4150 #4053 four-barrel on aluminum dual-plane intake; Holley rated the carb at 780 cfm while Chevrolet literature commonly called it 800 cfm. Dealer/over-the-counter cross-ram dual-quad hardware was also offered.
- Ignition
- Single-point Delco-Remy distributor standard; transistorized ignition optional
- Oil pan / sump
- Special baffled high-performance oil pan
- Production notes
- 1969 Z/28 production reached 20,302 cars. Camaro Research Group documents DZ as the only 1969 302 engine suffix; Norwood Z/28 cowl-tag identification later used X33 or X77 depending on trim configuration.
Service Specs
- Spark plug
- AC 43 standard Z/28 reference; hotter/colder plugs varied by use and tune-up chart
- Spark-plug gap
- 0.035 in factory Z/28 tune-up reference
- Ignition timing
- 4° BTDC initial timing is the documented factory Z/28 tune-up reference for 1968–69-era 302 applications
- Valve lash
- 0.030 in intake / 0.030 in exhaust hot-and-running factory setting for the 30-30 cam; modern cold-setting procedure commonly uses about 0.026/0.026 in on the base circle
- Fuel pressure
- 5.0–6.5 psi mechanical fuel-pump pressure at recommended idle (factory Z/28 tune-up reference)
Compatibility Notes
- Journal size and block details differ across the 1967–1969 production run; verify the exact block/crank combination before ordering rotating parts.
- Factory solid-lifter Z/28 combinations require correct lash and valvetrain maintenance.
Notable Applications
1967–1969 Camaro Z/28
Strengths
- Excellent high-rpm character
- Large 4.00-inch bore
- Legendary Z/28 heritage
Weaknesses / Watch-outs
- Less low-rpm torque than longer-stroke small-blocks
- Original high-performance parts can be expensive
Common Upgrades
- Period-correct solid-lifter cam combinations
- High-flow cylinder heads
- High-rise intake and tuned exhaust
Racing History & Legacy
The 302 was created for the Camaro Z/28 and is inseparable from Chevrolet's late-1960s Trans-Am racing effort.
One of the most celebrated high-revving small-block Chevrolets ever produced.
References & Image Credit
Engine image: BUTTON74 · CC BY-SA 4.0 · source
GM Heritage Archive vehicle information kits
manufacturer archive
Wikimedia Commons 1969 Camaro 302 engine image
licensed media
Camaro Research Group — Z/28, heads and carburetion research
specialist research
1969 Camaro fuel requirements / Z28 operating references
manufacturer owner manual
Factory Muscle replacement specification for GM 3849346 camshaft
aftermarket oem profile reference
Camaro Research Group — 302 OEM valve adjustment
specialist research
1968 Camaro Z/28 factory tune-up specifications
manufacturer specification
Camaro Research Group — tune-up document library
specialist archive
Camaro Research Group — 1969 Z/28 production and DZ suffix
specialist research
Key Factory / Build Variants
1968 Z/28 302
1968290 hp gross advertised
Refined the high-rpm formula and expanded the Z/28's reputation.
DZ 302
1969290 hp gross advertised
The most famous production-code version and a major collector reference point.
Engineering Notes Worth Knowing
01
The 4.00-inch bore supports larger valves and better breathing than the earlier 283-size bore.
02
Factory solid-lifter combinations demand correct lash and valvetrain maintenance.
03
Its short stroke trades some low-rpm torque for exceptional high-rpm character.
History · context · related reading
The Story Behind Chevy 302
The Chevrolet 302 exists because racing rules demanded it. Engineers paired a 4.00-inch bore with the old 3.00-inch stroke to land just under the SCCA Trans-Am displacement ceiling, creating one of the most purposeful production small-blocks of the muscle era.
Rulebook engineering
01How Trans-Am rules created the 302
The displacement limit that pushed Chevrolet toward a unique bore-and-stroke combination specifically for the Camaro Z/28.
Legend
02Why the DZ 302 became an icon
What made the 1969 version the engine enthusiasts remember, from its rev-happy personality to its Z/28 identity.
Comparison
03302 vs 350: rpm or street torque?
Why two 4.00-inch-bore small-blocks with different strokes feel completely different behind the wheel.
Documented motorsport results
Famous Race Wins
01
1968
1st in Trans-Am class · 3rd overall12 Hours of Sebring · Trans-Am class
Drivers
Mark Donohue & Craig Fisher
Car / engine
Roger Penske Chevrolet Camaro Z/28 · 302 V8
The 302 Z/28 won its class at Sebring
Donohue and Fisher took the Penske Camaro to a Trans-Am class victory at Sebring, one of the most important endurance-racing wins associated with Chevrolet’s 302.
02
1968
1st overallTrans-Am · War Bonnet Park
Driver
Mark Donohue
Car / engine
Sunoco/Penske Chevrolet Camaro Z/28 · 302 V8
Donohue won the War Bonnet Trans-Am round
The 302-powered Penske Camaro took pole and won at War Bonnet, beginning a dominant stretch in the 1968 Trans-Am campaign.
03
1968
1st overallTrans-Am · Lime Rock Park
Driver
Mark Donohue
Car / engine
Sunoco/Penske Chevrolet Camaro Z/28 · 302 V8
The 302 Camaro won again at Lime Rock
Donohue drove the Z/28 to another overall Trans-Am victory at Lime Rock, reinforcing the 302’s reputation as a purpose-built road-racing small-block.
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