Cadillac's 75th anniversary year arrived with a shock to traditionalists, as full-size models endured an eye-opening downsizing. "You must drive it," the ads declared, "to see why we call it the next generation of the luxury car." The new C-bodied DeVille, Brougham and limousine were 8 to 12 in. shorter, 3-1/2 in. narrower, and an average of 950 pounds lighter than their massive predecessors. Still, many models managed to keep the same leg room in front and rear (or even more). Only Eldorado carried on in its mammoth form a while longer, and Seville had entered life in 1975 with contemporary dimensions. Even the commercial chassis shrunk, from 157.5 down to 144.5 inches in wheelbase, requiring funeral car and ambulance suppliers to create some new bodies.

All models except Seville carried a new lighter, smaller 425 cu. in. (7.0-liter) V-8 engine. That powerplant emerged as the result of testing 110 experimental engines. The huge 500 V-8 was gone. Electronic fuel injection was optional in DeVille, Brougham, and Eldorado. Standard Turbo Hydra-matic fed power to low-ratio drive axles. Four-wheel disc brakes were standard on Seville, Eldorado and Brougham. Astroroofs and sunroofs were again available. Carryover special editions included Coupe and Sedan DeVille d'Elegance and Brougham 'Elegance.

One new special edition joined the lineup: the Eldorado Custom Biarritz. All sedans now had pillars and framed door glass. (The 'true' four-door hardtop was gone for good.) With Calais departed, DeVille took over as the cheapest Caddy (base price under $10,000). Dash gauges could be pulled out from the front for servicing. All models had a new two-spoke steering wheel -- but those were wide spokes. A new door design offered better hold-open qualities. Anti-corrosion treatment on all models included zinc-rich primers, hot melt sealers, wax coating, Plastisol-R-, and deadeners. Cadillac also expanded the use of Zincrometal-R- and bi-metal (stainless steel on aluminum), corrosion-resistant inner front fender panels, and elimination of areas that trapped dirt and water. Wheels and tires were now match-mounted for smoothest ride.

For 1977, there were five models:

I. D. DATA

All Cadillacs again had a 13-symbol Vehicle Identification Number (VIN) on the forward lower edge of the windshield frame, visible through the windshield.
The first digit ("6") identifies the Cadillac Division.
The second symbol denotes car line/series:
  • "S" Seville
  • "D" DeVille
  • "B" Fleetwood Brougham
  • "F" Fleetwood limousine
  • "L" Eldorado
  • "Z" commercial chassis
Digits three and four indicate body type:
  • "23" 4-door limousine with auxiliary seat
  • "33" 4-door formal limousine with partition window
  • "47" 2-door coupe
  • "69" 4-door pillared sedan
  • "90" commercial chassis (number identifies name of body builder)
Next comes the engine code:
  • "R" V8-350 EFI
  • "S" V8-425 4 Bbl.
  • "T" V8-425 EFI
Symbol six indicates model year ("7" 1977).
Seventh is an assembly plant code:
  • "Q" Detroit
  • "E" Linden, NJ
At the end is a six-digit sequence number:
  • running from 100001 to 400000 for C-bodies and Eldos built in Detroit
  • running from 450001 to 550000 for Sevilles from Detroit
  • running from 600001 to 690000 for C-bodies built in Linden
A nine-digit derivative of the VIN appears on the engine.
A Body Number Plate has codes for model year, model number, trim combination, body number (assembly plant and sequence built), paint color(s), and a number-letter code that shows the date built.
That plate is mounted on the upper left cowl between hood rear seal and windshield except Eldorado, on left side of cowl next to hood rear bumper; and Seville, riveted to cowl above evaporator case.

SPECIFICATIONS

FLUID CAPACITIES

EngineV8 350cc (5.7L)V8 425cc (7.0L)
Crankcase4 qt4 or 5 qt
Crankcase with new filter5 qt5 or 6 qt
AutomaticTransmission after draining8 pt8 or 10 pt
Drive Axle5 pt5 or 4 pt
Fuel tank21 gal(US)24.5 or 27.5 gal(US)
Cooling with heater17.2 qt21 or 26 qt
Cooling with A/C17.2 qt21 or 26 qt
Heavy duty CoolingNANA qt

GASOLINE ENGINE TUNE-UP SPECS

Engine V.I.N CodeRST
Engine typeV8-350cc(5.7L)V8-425cc(7.0L)V8-425cc(7.0L)
Fuel delivery4 bbl4 bblEFI
ManufacturerOldsmobileCadillacCadillac
Original Spark plugR47SXR45NSXR45NSX
Gap0.060 in.0.060 in0.060 in
DistributorElectronicElectronicElectronic
Ignition timing (BTDC)10° (6°)10°@1400 rpm18°@1400 rpm
Intake valve opens (BTDC)222121
Fuel pump pressure5¼ to 6½ psi5¼ to 6½ psi39 min.
Idle speed650 rpm675 rpm675 rpm

ALTERNATOR AND REGULATOR SPECS

Part #1102380110102311010331117152
Field current @ 12 V4 - 4.54 - 4.54 - 4.54 - 4.5
Output63 amps80 amps80 amps145 amps
RegulatorSolid stateSolid stateSolid stateSolid state
Volts @ 75°13.8 - 14.813.8 - 14.813.8 - 14.813.8 - 14.8

BATTERY AND STARTER SPECS

EngineV8-350cc (5.7L)V8-425cc (7.0L)
Battery Ampere Hour Capacity3500 watts cranking power @ 0°F
Battery Volts1212
Battery Terminal GroundedNeg.Neg.
Starter, Lock Test, AmpsNot RecommendedNot Recommended
Starter, Lock Test, Volts
Starter, Lock Test, Torque
Starter, No-Lead Test, Amps65 - 9565 - 95
Starter, No-Lead Test, Volts99
Starter, No-Lead Test, RPM7000 - 105007000 - 10500
Starter, Brush Spring Tension35 oz. min.35 oz. min.

GENERAL ENGINE SPECS

Engine V.I.N CodeRST
Engine typeV8-350cc(5.7L)V8-425cc(7.0L)V8-425cc(7.0L)
ManufacturerOldsmobileCadillacCadillac
Fuel deliveryEFI4 bblEFI
Horsepower180@4400180@3600215@3600
Torque275@2000260@2000260@2000
Bore x Stoke4.057 x 3.3854.082 x 4.0604.082 x 4.060
Compression Ratio8.00:18.50:18.50:1
Oil pressure35 psi35 psi35 psi

CRANKSHAFT SPECS

Engine typeV8-350cc(5.7L)V8-425cc(7.0L)
Main Brg Journal Dia.2.4985 - 2.4995 (No. 1 2.4988 - 2.4998 in)3.250
Main Brg Oil Clearance0.0005 - 0.0021 (No. 5 0.0015 - 0.0031in)0.0001 - 0.0026
Shaft End-play0.004 - 0.0140.002 - 0.012
Thrust on No.33

CONNECTING ROD SPECS

Engine typeV8-350cc(5.7L)V8-425cc(7.0L)
Journal Dia.2.1238 - 2.12482.5000
Oil Clearance0.0004 - 0.00330.0005 - 0.0028
Side Clearance0.006 - 0.0200.008 - 0.020

PISTON AND RING SPECS

Engine typeV8-350cc(5.7L)V8-350cc(5.7L) DieselV8-425cc(7.0L)
Piston-Bore Clearance0.0010 - 0.00200.0005 - 0.00060.0006 - 0.0014
Ring Side Clearance: Top Compression0.0020 - 0.00400.005 - 0.0070.0017 - 0.0040
Ring Side Clearance: Bottom Compression0.0020 - 0.00400.0018 - 0.00380.0017 - 0.0040
Ring Side Clearance: Oil Control0.0006 - 0.00980.0078 max.None (side sealing)
Ring Gap: Top Compression0.010 - 0.0230.015 - 0.0250.013 - 0.023
Ring Gap: Bottom Compression0.010 - 0.0230.015 - 0.0250.013 - 0.023
Ring Gap: Oil Control0.015 - 0.0550.015 - 0.0550.015 - 0.055

VALVE SPECS

Engine typeV8-350cc(5.7L)V8-350cc(5.7L) DieselV8-425cc(7.0L)
Seat Angle31°(exh)45°(intake); 31° (exhaust)45°
Face Angle30° (exh)44°(intake); 30° (exhaust)44° (exh)
Spring Test Pressure187 lb @ 1.27 in.151 lb @ 1.30 in.160 lb @ 1.50 in.
Spring Installed Height1-43/64"1-43/64"11516 in.
Stem-to-Guide Clearance: Intake0.0010 - 0.00270.0010 - 0.00270.0010 - 0.0027
Stem-to-Guide Clearance: Exhaust0.0015 - 0.00320.0015 - 0.00320.0010 - 0.0027
Stem Diameter: Intake0.34290.34290.3416
Stem Diameter: Exhaust0.34240.34240.3416

TORQUE SPECS

Engine typeV8-350cc(5.7L)V8-350cc(5.7L) DieselV8-425cc(7.0L)
Cyl. Head Bolts130 ft.lb130 ft. lb90 ft. lb
Rod Brg Bolts42 ft.lb42 ft. lb40 ft. lb
Main Brg Bolts80 ft.lb (120 on # 5)120 ft. lb90 ft. lb
Crankshaft Damper or Pulley Bolt310 ft.lb200 - 310 ft.lbPress fit
Flywheel to Crankshaft Bolts60 ft.lb60 ft. lb75 ft. lb
Intake Manifold40 ft.lb40 ft. lb30 ft. lb
Exhaust Manifold25 ft.lb25 ft. lb22 ft. lb

CARBURETOR SPECS

Carb ID17057232 (M4ME)17057233 (M4ME)17057230 (M4ME)17057231 (M4ME)17057530 (M4ME)17057533 (M4ME)
Float Level13/32 in13/32 in13/32 in17/32 in13/32 in13/32 in
Air Valve Spring1/2 turn1/2 turn1/2 turn1/2 turn1/2 turn1/2 turn
Pump Rod3/8 in3/8 in7/16 in3/8 in7/16 in7/16 in
Primary Vacuum Break0.140 in0.140 in0.140 in0.140 in0.150 in0.150 in
Secondary Vacuum Break0.140in 0.140in0.140 in0.140in 0.150in0.150 in
Choke Rod0.080 in0.080 in0.080 in0.080 in0.080 in0.080 in
Choke Unloader0.230 in0.230 in0.230 in0.230 in0.230 in0.230 in
Fast Idle Speed1400 rpm1400 rpm1400 rpm1400 rpm1500 rpm1500 rpm

WHEEL ALIGNMENT SPECS

Feature Eldorado Full size Seville
Caster Range 1°N - 1°P 2°P - 4°P 1°P - 3°P
Caster Pref. 3°P 2°P
Camber LH wheel Range ¾°N - ¾°P ¼°N - 1¼°P ¾°N - ¾°P
Camber LH wheel Pref. ½°
Camber RH wheel Range ¾°N - ¾°P ¼°N - 1¼°P ¾°N - ¾°P
Camber RH wheel Pref. ½°
Toe-In 0" 0" 1/16"
Steering Axis Inclination10-19/32° 10-5/8°

HISTORICAL NOTES

1977 Cadillac Notes

Sedan de Ville95,421 (increased 27,744)
Coupe de Ville138,750 (increased 24,268)
Eldorado47,344 (decreased 1,840)
Seville45,060 (increased 1,288)
Series 6028,000 (increased 3,500)
Series 753,913 (increased 589)