Engine profile

AMC 390 V8

AMC Gen-2/Gen-3 V8 · 390 cubic inches · American Motors

1968 AMC AMX 390 Go Package automatic engine-bay context; visual context, not individual-car proof. 1968 AMC AMX 390

Engine Summary

Manufacturer: American Motors
Family: AMC Gen-2/Gen-3 V8
Displacement: 390 cubic inches

Also Known As

AMC 390390 AMC V8390 CID AMC V-8390 cu in AMC V8390-cubic-inch AMC V-8Machine 390Rebel Machine 390390 Rebel Machinespecial 340 HP 390 CID340 hp 390315 hp 390SC/Rambler 390Hurst SC/Rambler 390390 CID AMC V8 from the AMXAMX 3901970 AMX 3901968 AMX 390325 hp 3901970 Javelin 3901970 Javelin SST 390Mark Donohue 390Javelin Mark Donohue 390

Identification reference

Engine Details

Source-backed component numbers, codes, stampings, and application notes.

Air-cleaner element

Value: Cellulose fiber element
Application: 1969 AMC 390 CID V-8 carburetor air cleaner
Type: air cleaner / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Cylinder block material

Value: Cast iron
Application: 1969 AMC 390 CID V-8
Type: block / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Cylinder block material

Value: Cast iron
Application: 1970 AMC 390 CID V-8
Type: block / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Engine-size block casting location

Value: Engine size cast into each side of the block between the freeze plugs behind the mounting plates
Application: 1970 Gen 3 AMC 390 V-8 identification
Type: block / other
Car pages: 1970 AMC Javelin SST 390

Identification aid only; this does not establish an individual car's original engine without VIN, tag, date, and paperwork agreement.

Sources: Identifying the Gen 2 and Gen 3 V-8 Engines

Automatic-transmission carburetor

Value: Carter AFB 4665S, 4-barrel
Application: 390 CID, 315 hp V-8 with automatic transmission
Type: carburetor / carburetor list
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Carburetion

Value: Single 4-barrel downdraft carburetor
Application: 1970 AMC 390 CID V-8 passenger-car application
Type: carburetor / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Manual-transmission carburetor

Value: Carter AFB 4664S, 4-barrel
Application: 390 CID, 315 hp V-8 with manual transmission
Type: carburetor / carburetor list
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Crankshaft material

Value: SAE 1046 forged steel
Application: 1969 AMC 390 CID V-8
Type: crankshaft / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

1970 early 390 dog-leg head valve sizes

Value: 2.025 in. intake; 1.625 in. exhaust
Application: 1970 AMC 390 early dog-leg cylinder head casting 3196291
Type: cylinder head / specification
Car pages: 1970 AMC Javelin SST 390

Sources: Identifying the Gen 2 and Gen 3 V-8 Engines

1970 Gen 3 390 dog-leg cylinder-head casting

Value: 3196291
Application: 1970 AMC Gen 3 390 V-8 cylinder heads
Type: cylinder head / casting number
Car pages: 1970 AMC Javelin SST 390

AHPS reports this casting for 1970 Gen 3 390 heads; individual-car originality still requires date and paperwork correlation.

Sources: Identifying the Gen 2 and Gen 3 V-8 Engines

1970 late 390 dog-leg head valve sizes

Value: 2.025 in. intake; 1.680 in. exhaust
Application: 1970 AMC 390 late dog-leg cylinder head casting 3196291
Type: cylinder head / specification
Car pages: 1970 AMC Javelin SST 390

Sources: Identifying the Gen 2 and Gen 3 V-8 Engines

Cylinder head material

Value: Cast iron
Application: 1969 AMC 390 CID V-8
Type: cylinder head / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Cylinder head material

Value: Cast iron
Application: 1970 AMC 390 CID V-8
Type: cylinder head / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Bore and stroke

Value: 4.165 x 3.574 in
Application: 1969 AMC 390 CID V-8
Type: engine assembly / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Bore and stroke

Value: 4.165 x 3.574 in.
Application: 1970 AMC 390 CID V-8
Type: engine assembly / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Compression ratio

Value: 10.2:1 nominal
Application: 1969 AMC 390 CID V-8 with 4-barrel carburetor
Type: engine assembly / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Compression ratio

Value: 10.0:1 nominal
Application: 1970 AMC 390 CID V-8, 4-barrel passenger-car application
Type: engine assembly / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Engine type and induction

Value: 90-degree OHV V-8 with 4-barrel carburetor
Application: 1969 AMC 390 CID V-8, AMX optional engine
Type: engine assembly / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Published maximum horsepower

Value: 315 bhp at 4,600 rpm
Application: 1969 AMC 390 CID V-8 with 4-barrel carburetor
Type: engine assembly / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Published maximum output

Value: 325 bhp @ 5000 rpm; 420 lb-ft @ 3200 rpm
Application: 1970 AMC 390 CID V-8, 4-barrel Javelin passenger-car application; excludes the separate Rebel Machine 340 hp version
Type: engine assembly / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Published maximum torque

Value: 425 lb-ft at 3,200 rpm
Application: 1969 AMC 390 CID V-8 with 4-barrel carburetor
Type: engine assembly / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Recommended fuel

Value: Premium
Application: 1970 AMC 390 CID V-8, 4-barrel passenger-car application
Type: engine assembly / specification
Car pages: 1970 AMC Javelin SST 390

Sources: 1970 AMC AMA Specifications - Passenger Cars

Ignition system type

Value: Conventional ignition standard; transistorized/capacitor-discharge ignition not available
Application: 1969 AMC 290, 343, and 390 CID V-8 engines
Type: ignition / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car

Piston construction

Value: Autothermic flat-top piston with valve pockets, slipper skirt, tin plate, and steel-strut inserts
Application: 4-barrel 390 CID AMC V-8
Type: piston / specification
Car pages: 1969 AMC AMX 390

Sources: 1969 American Motors AMA Specifications - Passenger Car