Description
About This Engine
The AMC 360 is the longest-lived V8 engine American Motors Corporation ever built- produced continuously from 1970 through 1991, ending its automotive life as the standard engine in the last Jeep Grand Wagoneer that rolled off the line in 1991. AMC introduced the 360 in 1970 as a direct development of the 343 cubic inch engine from the 1966 to 1969 era, increasing deck height and stroke to achieve the larger displacement. Its defining characteristic was straightforward American V8 engineering executed well: high-nickel cast iron block, non-siamesed cylinder bores with water between all cylinders, 2.025-inch intake valves with dog-leg exhaust ports, and 2-bolt main caps that provided more than adequate strength for the engine's intended operating range.
In AMC car applications- the AMX, Javelin, Hornet, and Matador- the 360 produced up to 290 hp (SAE gross) in 1970. The compression and output fell through the 1970s as emissions regulations arrived. By the late 1970s, the detuned 360 was producing as little as 125 hp. When Chrysler acquired AMC in 1987 and retuned the engine for the final Grand Wagoneer applications, output settled at 144 hp- honest and adequate for a 5,000-pound luxury SUV.
The Jeep Grand Wagoneer with the AMC 360 is the dominant application in today's used engine market. Grand Wagoneers are having a cultural moment- original examples in good condition regularly sell for $30,000 to $80,000 or more, and the 360 is integral to the vehicle's identity and value. A compression-tested, rear-main-checked AMC 360 with documented casting numbers is a meaningful find for any Grand Wagoneer restoration.
Signs You Need a Replacement Engine
- Oil leak at the rear main seal- the AMC 360's most common and most chronic issue. The rope-style rear main seal is a known seep point on aged engines. We specifically inspect and report on rear main seal condition before shipping.
- Knock under load- rod or main bearing wear on high-mileage examples
- Low oil pressure at idle after warmup- main bearing wear or oil pump wear
- Oil leaks at the intake manifold and timing cover- common on aged AMC V8 engines
- Loss of compression on one or more cylinders- ring wear or scored cylinder walls
- Rough idle that varies with engine temperature- worn cam lobes on engines run on low-zinc modern oil
Known Problems With This Engine
- Rear main seal- the AMC 360's most notorious issue: The rope-type rear main seal used by the AMC 360 is a chronic seep point on aged engines. It is not a catastrophic leak in most cases but is persistent and cosmetically objectionable. We specifically assess and report on rear main seal condition before every unit ships.
- Oiling system valley line concern on high-performance builds: At sustained high RPM (not relevant for stock Jeep operation), the AMC 360's oil supply to the front of the valley can be insufficient. This is addressed with the 'valley oil line' modification- routing an additional oil line under the intake manifold. This is not needed for normal street and trail driving but is relevant for anyone building a higher-output 360.
- 2-bolt main caps- stock only: AMC never built a factory 4-bolt main block. Stock 2-bolt mains are entirely adequate for street and trail use at stock output levels. For a built engine producing sustained high power, aftermarket 4-bolt main cap kits are available.
- Aluminum bridged rocker arms from 1974 onward: Post-1974 360s use bridged aluminum rocker arms rather than the earlier individual rocker pedestals. The bridged rockers are less suited to high-performance camshaft upgrades. For a stock replacement, both types are adequate. We note rocker arm type before shipping.
- SAE gross vs net output confusion: The 1970 to 1971 360 was rated at 290 hp SAE gross. From 1972, all outputs were rated SAE net (lower, more accurate numbers measured with accessories installed). The engine did not actually lose that much power in 1972- the rating method changed. A 1972 360 rated at 175 hp SAE net is producing approximately the same actual power as a 1970 360 rated at 245 hp SAE gross in real-world conditions.
AMC 360 by Year and Application
Key milestones across the AMC 360's 21-year production life:
| Years | Application | HP (SAE) | Compression | Notes |
|---|---|---|---|---|
| 1970 | AMC cars (AMX, Javelin, etc.) | 290 hp gross | 10.0:1 | First year. 4-barrel carb high-output version. Individual rocker pedestals. Highest compression 360. |
| 1971 to 1972 | AMC cars and Jeep (first Jeep year) | 195 hp gross, 175 hp net | 8.5:1 | Compression dropped for emissions. Rating method changed to net in 1972- appears lower but similar real-world output. |
| 1972 to 1978 | Jeep Wagoneer, Cherokee, J-series, AMC cars | 145 to 175 hp net | 8.25:1 | Bridged aluminum rocker arms from 1974. Emissions equipment. Steady detuning through decade. |
| 1979 to 1983 | Jeep Grand Wagoneer, Cherokee, J-truck | 125 to 140 hp net | 8.25:1 | Lowest output era. Emissions at peak restrictions. |
| 1984 to 1991 | Jeep Grand Wagoneer (final years) | 144 hp net | 8.25:1 | Slight output improvement. Chrysler continued production after 1987 AMC acquisition. Block casting reads '5.9L' from 1987 onward. |
Common Casting Numbers
| 3205490 | 1970 to 1971 AMC 360 block |
|---|---|
| 3205893 | 1972 to 1973 360 block |
| 3210454 / 3214693 | 1974 to 1979 360 block- most common restoration era |
| 3239832 | 1980 to 1991 Jeep 360/5.9L block- final generation |
Casting number documented before shipping.
What Is Included- What Is Not Included
| INCLUDED- Long Block | Block, crankshaft, pistons, connecting rods, camshaft, cylinder heads, valve train, oil pan, front timing cover, and water pump where present. |
|---|---|
| NOT INCLUDED | Intake manifold, carburetor, exhaust manifolds, distributor and ignition system, alternator, power steering pump, starter, flexplate or flywheel, accessory brackets. |
| Core Note | No core charge. You are not required to return your old engine. |
Vehicle Compatibility
The AMC 360 was factory installed in the following vehicles:
| Jeep Grand Wagoneer (SJ) | 1972 to 1991- primary Jeep application and largest used engine market today |
|---|---|
| Jeep Cherokee (SJ) | 1974 to 1983- full-size Cherokee, not the XJ Cherokee that came later |
| Jeep J-Series Trucks (J10 and J20) | 1972 to 1987 |
| AMC AMX | 1971 to 1974 |
| AMC Javelin | 1971 to 1974 |
| AMC Hornet S/C 360 | 1971- 285 hp 4-barrel version |
| AMC Matador | 1971 to 1977 |
| Bricklin SV-1 | 1974- Canadian sports car using AMC 360 |
The AMC 304, 360, and 401 all share identical external dimensions, bellhousing bolt pattern, and motor mount locations. The 360 is a direct swap into any vehicle that originally used the 304 or 401. The AMC/Jeep bellhousing pattern is unique- not compatible with GM, Ford, or Chrysler transmissions without an adapter. The Jeep Quadra-Trac, Turbo Hydra-Matic, and various manual transmissions are the correct pairings.
Transmission compatibility: Chrysler Torqueflite A727- standard automatic pairing in most Jeep applications | Turbo Hydra-Matic (early 1970s AMC car applications) | Jeep Quadra-Trac 4WD system | AMC T-18 or T-15 manual | SR4 4-speed manual- some applications. Confirm your specific application before ordering.
Not sure if this fits? Call (240) 301-0095. We verify fitment before every order ships.
Common Names and Search Terms
| AMC 360 | Most common buyer search |
|---|---|
| Jeep 360 | Application designation |
| AMC 360 V8 | Configuration search |
| 5.9L AMC engine | Liter-format buyer |
| Grand Wagoneer engine | Premium application buyer |
| AMC 5.9 | Short liter designation |
| Jeep 360 5.9 | Combined designation buyer |
| AMC V8 360 | Full designation |
| 360 AMC Jeep | Reversed search |
| AMC 360 replacement | Replacement buyer intent |
Used OEM vs Rebuilt- Which Is Right for You?
Used OEM is the right choice for a Grand Wagoneer, Cherokee, or J-series truck restoration where a compression-tested, rear-main-checked engine with casting documentation is the foundation. Our 360 units are documented with year, application, rocker arm type, and rear main seal condition before shipping.
A professionally rebuilt AMC 360 makes sense for a Grand Wagoneer concours restoration or a performance build targeting 300 to 400 hp. AMC/Jeep specialists can rebuild the 360 with fresh tolerances, updated rear main seal conversion to a modern lip seal, and appropriate camshaft. Call us to discuss sourcing options.
Condition and Inspection Process
- Compression test across all 8 cylinders- results per cylinder recorded before shipping
- Rear main seal condition specifically assessed- the AMC 360's most common failure point inspected and reported
- Year and application confirmed- Jeep vs AMC car application documented, rocker arm type noted (pre-1974 individual vs post-1974 bridged)
- Casting number documented where readable- block year generation noted
- Timing cover and gasket surfaces inspected for seepage
- Valve cover inspection for sludge and cam wear indicators
- Valley area inspected for oil pooling indicators on high-mileage units
Mileage varies by unit. Where available from the donor vehicle we provide it. Where it cannot be confirmed, we disclose this before your order is placed.
Buyer Tips- What to Know Before You Order
- Rear main seal replacement: Any AMC 360 of significant mileage should have the rear main seal replaced at installation. Modern rope seal replacement kits and lip seal conversion kits are available from AMC suppliers (Spitfire, Advance Adapters). The lip seal conversion is a popular upgrade over the original rope seal.
- Modern oil with ZDDP: The AMC 360 uses a flat-tappet hydraulic camshaft. Modern low-zinc oils (SN rating) are insufficient for flat-tappet cam lubrication. Use an oil with ZDDP zinc supplement added or use an oil specifically rated for flat-tappet applications (ZDDP Plus, Driven, or similar).
- Aftermarket support: The AMC 360 has good aftermarket support from suppliers including Melling (oil pumps), Sealed Power (engine rebuild kits), and Edelbrock (intake manifolds and carburetors). Summit Racing and Speedway Motors maintain AMC-specific catalogs. Connect with the AMC community (AMC Forum, Jeep Garage) before building.
- Grand Wagoneer context: A Grand Wagoneer with original matching-number 360 commands a premium in the collector market. If you are sourcing a 360 for a Wagoneer restoration, document the casting numbers of both the engine and the original block for provenance purposes.
- The 304 and 360 are the same stroke: If you need a 360 but find a well-preserved 304, the 304 block cannot become a 360 by changing the bore- the bore spacing on the 304 block allows maximum bore sizes that top out below 360 displacement. They are separate castings.
Why Buy From Vaz Auto Solutions
- Rear main seal condition specifically assessed- the AMC 360's most notorious issue flagged and reported before every order
- Compression tested across all 8 cylinders- results shared before order confirmed
- Year and application documented- Jeep vs AMC car, rocker arm type noted
- Casting number documented where readable
- No core charge- keep your old engine
- Free freight pallet delivery to all 50 states
- 15 day replacement warranty on internal engine defects
- Call (240) 301-0095- speak with someone who understands AMC 360 year distinctions, Grand Wagoneer applications, and the AMC/Jeep V8 engine family
David Smith (verified owner) –
I bought an AMC 360 Engine from Vaz Auto Solutions and couldn’t be happier. The engine arrived promptly and was exactly as described. It runs smoothly and has significantly improved my vehicle’s performance. Highly recommend
Michael Johnson (verified owner) –
My experience with Vaz Auto Solutions was quite positive. I purchased the AMC 360 Engine and it arrived on schedule, packaged securely. The engine performs exceptionally well
James W., Scottsdale AZ –
Sourcing a tested AMC 360 for a Grand Wagoneer is genuinely hard. Vaz checked the rear main seal- the thing everyone worries about- and reported a minor seep that they caught before shipping. Had the seal replaced at install with the modern lip seal conversion. Compression came back 152 to 162 across all 8. Wagoneer runs perfectly. They also documented the block casting which I needed for the restoration records.
Phil R., Phoenix AZ –
Replaced the 360 in my J10 after a spun main bearing. Vaz confirmed the year and Jeep application, tested all 8 cylinders, and reported on the rear main seal. Timing cover was seeping slightly- disclosed before I bought. Replaced it at installation for $22. Truck runs strong. Good honest company that understands AMC engines.