Identification reference
Engine Details
Source-backed component numbers, codes, stampings, and application notes.
390-4V block geometry
- Value
- Cast-iron block and heads; 4.054-inch bore, 3.78-inch stroke, 4.63-inch bore spacing, and 1-5-4-2-6-3-7-8 firing order
- Application
- Factory AMA specification for 63H hardtop and 76H convertible GT/GTA
- Type
- block / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Bore and stroke
- Value
- 4.05 x 3.78 inches
- Application
- 1967 Marauder 390 GT four-barrel
- Type
- block / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications , 1967 Mercury full-line sales brochure
Detailed block geometry
- Value
- Cast-iron block and heads; 4.054-inch bore, 3.78-inch stroke, 4.63-inch bore spacing, and 1-5-4-2-6-3-7-8 firing order
- Application
- Factory 1967 Marauder 390 GT four-barrel specification
- Type
- block / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Camshaft and valve timing
- Value
- In-block, chain-driven camshaft with 48-link chain; 270-degree intake and exhaust duration, 44-degree overlap, and 0.4809-inch intake and exhaust lift at zero lash
- Application
- Factory 390 GT valve-timing specification
- Type
- camshaft / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Camshaft and valve timing
- Value
- In-block, chain-driven camshaft with 48-link chain; 270-degree intake and exhaust duration, 40-degree overlap, and 0.4809-inch intake and exhaust lift at zero lash
- Application
- Factory 390-4V valve-timing specification
- Type
- camshaft / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Automatic-transmission Holley
- Value
- C7OF-B four-barrel with 1.562-inch primary and secondary bores
- Application
- C6 Select-Shift Merc-O-Matic 390 GT applications
- Type
- carburetor / engineering number
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Automatic-transmission Holley
- Value
- C6OF-9510-N four-barrel with 1.562-inch primary and secondary bores
- Application
- Merc-O-Matic and Sport Shift applications
- Type
- carburetor / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Exhaust-emission-control carburetor calibration
- Value
- C7OF-C with manual transmission; C7OF-D with automatic transmission
- Application
- Only the exhaust-emission-control 390 GT configurations in the AMA supplements, not a universal 390 GT identifier
- Type
- carburetor / engineering number
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Ford carburetor engineering number
- Value
- C70E-9510-D
- Application
- 1967 Mustang G.T. 390 engine, automatic transmission application
- Type
- carburetor / engineering number
Holley numerical listing pairs this Ford number with Holley list R-3796A.
Sources: Holley Numerical Listings, page 26
Ford carburetor engineering number
- Value
- C70E-9510-C
- Application
- 1967 Mustang G.T. 390 engine, standard transmission application
- Type
- carburetor / engineering number
Holley numerical listing pairs this Ford number with Holley list R-3795A.
Sources: Holley Numerical Listings, page 26
Holley 4150-C carburetor list number
- Value
- R-3796A
- Application
- 1967 Mustang G.T. 390 engine, automatic transmission application
- Type
- carburetor / carburetor list
Holley numerical listing pairs this list number with Ford C70E-9510-D.
Sources: Holley Numerical Listings, page 26
Holley 4150-C carburetor list number
- Value
- R-3795A
- Application
- 1967 Mustang G.T. 390 engine, standard transmission application
- Type
- carburetor / carburetor list
Holley numerical listing pairs this list number with Ford C70E-9510-C.
Sources: Holley Numerical Listings, page 26
Induction and fuel
- Value
- Single four-barrel carburetor; premium fuel
- Application
- 1967 Cyclone GT
- Type
- carburetor / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications , 1967 Mercury full-line sales brochure
Manual-transmission Holley
- Value
- C7OF-A four-barrel with 1.562-inch primary and secondary bores
- Application
- Three- and four-speed manual 390 GT applications
- Type
- carburetor / engineering number
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Manual-transmission Holley
- Value
- C6OF-9510-M four-barrel with 1.562-inch primary and secondary bores
- Application
- Three- and four-speed manual applications
- Type
- carburetor / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Connecting rods and piston pins
- Value
- 6.488-inch forged SAE 1041 steel rods with full-floating 0.9752-inch tubular alloy-steel piston pins and bronze rod bushings
- Application
- Factory 390 GT engine-component specification
- Type
- connecting rod / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Connecting rods and piston pins
- Value
- 6.488-inch forged SAE 1041 steel rods with full-floating 0.9752-inch tubular alloy-steel piston pins and bronze rod bushings
- Application
- Factory 390-4V engine-component specification
- Type
- connecting rod / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Crankshaft and damper construction
- Value
- Precision-molded cast-iron-alloy crankshaft with a rubber-floated vibration damper and 0.004-0.008-inch end play
- Application
- Factory 390 GT assembly specification; not a casting-number or individual-engine identifier
- Type
- crankshaft / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Crankshaft and damper construction
- Value
- Precision-molded cast-iron-alloy crankshaft with a rubber-floated vibration damper and 0.004-0.008-inch end play
- Application
- Factory 390-4V assembly specification; not a casting-number or individual-engine identifier
- Type
- crankshaft / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Compression and fuel
- Value
- 10.5:1 compression with premium fuel
- Application
- All documented 1966 Cyclone GT and GTA power teams
- Type
- engine assembly / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications , 1966 Mercury and Mercury Comet full-line brochure
Cyclone GT 390-4V
- Value
- 390 cu in FE V8, 335 gross hp at 4,800 rpm and 427 lb-ft at 3,200 rpm
- Application
- GT and GTA hardtop or convertible
- Type
- engine assembly / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications , 1966 Mercury and Mercury Comet full-line brochure
Factory idle-speed settings
- Value
- 575-600 rpm in neutral with a manual transmission; 475-525 rpm in drive with an automatic
- Application
- 1966 Cyclone GT/GTA 390-4V tune-up baseline
- Type
- engine assembly / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Factory idle-speed settings
- Value
- 575-625 rpm in neutral with a manual transmission; 475-525 rpm in drive with an automatic, with headlamps off
- Application
- 1967 Cyclone GT 390-4V tune-up baseline
- Type
- engine assembly / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
GT exhaust and valvetrain
- Value
- Dual exhaust with hydraulic valve lifters
- Application
- Factory Cyclone GT power team
- Type
- engine assembly / specification
Sources: 1966 Mercury and Mercury Comet full-line brochure
Marauder 390 GT four-barrel
- Value
- 320 hp at 4,800 rpm; 427 lb-ft at 3,200 rpm; 10.5:1 compression
- Application
- standard Cyclone GT powertrain
- Type
- engine assembly / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications , 1967 Mercury full-line sales brochure
Exhaust-emission-control distributor calibration
- Value
- C7OF-F distributor; 4-8 degrees BTDC initial timing with transmission-specific idle procedure
- Application
- Only the exhaust-emission-control manual and automatic 390 GT configurations in the AMA supplements
- Type
- ignition / engineering number
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Dual exhaust dimensions
- Value
- Dual reverse-flow mufflers with 2.00-inch laminated branch pipes, 2.25-inch main pipes, and 2.25-inch tail pipes
- Application
- Factory Cyclone GT 390-4V exhaust system
- Type
- other / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Dual exhaust dimensions
- Value
- Dual reverse-flow mufflers with 2.00-inch branch, main, and tail pipes
- Application
- Factory Cyclone GT/GTA 390-4V exhaust system
- Type
- other / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Exhaust system
- Value
- Dual exhaust
- Application
- standard GT Performance Group equipment
- Type
- other / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications , 1967 Mercury full-line sales brochure
Fuel-delivery system
- Value
- Mechanical fuel pump at the left front of the engine, 4.5-5.5 psi pressure, and dry replaceable-element air cleaner
- Application
- Factory 390 GT fuel-system specification
- Type
- other / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Lubrication system
- Value
- Rotor oil pump, full-flow filter, 57-67 psi at 2,000 rpm, and 4.0-quart crankcase capacity excluding the filter refill
- Application
- Factory 390 GT service specification
- Type
- other / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Lubrication system
- Value
- Rotor oil pump, full-flow filter, 50-60 psi at 2,000 rpm, and 4.0-quart crankcase capacity excluding the filter refill
- Application
- Factory 390-4V service specification
- Type
- other / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Hydraulic valvetrain dimensions
- Value
- Hydraulic lifters with 1.73:1 rocker ratio, 2.022-2.037-inch intake valve heads, and 1.551-1.566-inch exhaust valve heads
- Application
- Factory 390 GT valvetrain specification
- Type
- valve train / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications
Hydraulic valvetrain dimensions
- Value
- Hydraulic lifters with 1.73:1 rocker ratio, 2.022-2.037-inch intake valve heads, and 1.551-1.566-inch exhaust valve heads
- Application
- Factory 390-4V valvetrain specification
- Type
- valve train / specification
Sources: 1966 Comet Cyclone GT and GTA AMA specifications
Valve lifters
- Value
- Hydraulic
- Application
- 1967 Marauder 390 GT four-barrel
- Type
- valve train / specification
Sources: 1967 Mercury Cyclone and Cyclone GT AMA specifications , 1967 Mercury full-line sales brochure
