CYLINDER CASE
YEARS	1990-92	1993-1995
Material	Aluminum casting	Same
Descriptions	Open deck 2-bolt fastening per bearing panel	Open deck 4-bolt fastening per bearing panel
Bore Spacing	111.76 mm (4.40 in.)	Same
Deck Height	229.24 mm (9.03 in.)	Same
Supplier	Dennison Foundry	GM Bedford

CRANKCASE
YEARS	1990-92	1993-1995
Material	Aluminum, with cast-in nodular cast iron bearing inserts	Same
Description	Ladder frame 2-bolt fastening per bearing panel	Ladder frame 4-bolt fastening per bearing panel

CYLINDER LINER
YEARS	1990-92	1993-1995
Material	Forged aluminum Nikasil coated	Same
Supplier	Mahle	Same

MAIN BEARINGS
YEARS	1990-92	1993-1995
Material	Lead-indium overlay	Same
Description	Cast leaded bronze steel-backed	Same
Supplier	Vandervell	Same

INLET VALVES
YEARS	1990-92	1993-1995
Material	VMS-648 Flash chrome	Same
Overall Length	103.17 mm (4.06 in.)	102.67 mm (4.04 in.)
Head Diameter	39 mm (1.54 in.)	Same
Angle Seat/Face	44 degree/45 degree	Same
Stem Diameter	7.96 mm (0.314 in.)	Same
Valve Angle	10 degree	Same
Valve Seat Diameter	37.2 mm (1.46 in.) gauge diameter	Same
Lift	9.9 mm	Same
Supplier	TRW	Same

EXHAUST VALVE
YEARS	1990-92	1993-1995
Material	VMS-478 Seat:VMS-590 Chrome flashed	VMS-478 Seat:VMS-637 Chrome flashed
Overall Length	103.47 mm (4.07 in.)	102.97 mm (4.05 in.)
Head Diameter	35.2 mm (1.39 in.)	Same
Angle Seat/Face	44 degree/45 degree	Same
Stem Diameter	7.96 mm (0.314 in.)	Same
Valve Angle	12 degree	Same
Valve Seat Diameter	33 mm (1.30 in.) gauge diameter	Same
Lift	9.9 mm (0.39 in.)	Same
Supplier	TRW	Same

VALVE SPRINGS
YEARS	1990-92	1993-1995
Type	Inner & outer opposed winding	Same
Load-Closed	160-313 N (36-70 lbs.)	Same
Load-Open	350-696 N (78-157 lbs.)	Same
Supplier	Tempered Spring	Same

VALVE LIFTERS
YEARS	1990-92	1993-1995
Material	Alloy cast iron	Same
Type	Hydraulic	Same
Supplier	AC Rochester	Same

CYLINDER HEAD
YEARS	1990-92	1993-1995
Material	Aluminum	Same
Description	Cross flow, fast burn, pent roof combustion chamber	Same
Combustion Chamber Volume	40 cc	Same
Gasket	Composition (Goetze)	Same
Supplier	Birmal	1995 1/2 model year-A.L. Dunn (design changes 1993-95)

FLYWHEEL
YEARS	1990-92	1993-1995
Material	Cast iron	Same
Description	Dual mass	Same
Supplier	LUK	Same

OIL PUMP
YEARS	1990-92	1993-1995
Type	Duo-centric-crankshaft driven	Same
Pressure	50-60 psi	Same
Temp Regulation	Thermostat-Open-95 degree C Fully open-130 degree C	Same
Capacity	Idle-1.6 gpm 7,000 rpm-9.1 gpm	Same
Supplier	Presta	SHW (minor design change, 1993-95 model years)

OIL PAN
YEARS	1990-92	1993-1995
Material	Aluminum	Same
Capacity	9.6 qts.	Same
Supplier	Stahl Specialty	Stahl Specialty (design changed, 1993-95 model years)

PLENUM
YEARS	1990-92	1993-1995
Material	Aluminum	Same
Supplier	Stahl Specialty	Stahl Specialty (design changed, 1993-95 model years)

CRANKSHAFT
YEARS	1990-92	1993-1995
Material	Nitrided	Same
Counterweights	6	Same
Crankpin Journal	53.33 mm (2.10 in.)	Same
Crankpin Splay	None	Same
Thrust Position	Bearing No. 3	Same
Main Journal Diameter	70.00 mm (2.76 in.)	Same
Supplier	Shardlow	Same

CONNECTING ROD
YEARS	1990-92	1993-1995
Material	Forged steel	Same
Length (CTR distance)	145.8 mm (5.74 in.)	Same
Supplier	Albon Engineering	Albon Engineering (rods lightened, 1993-95)

PISTON
YEARS	1990-92	1993-1995
Material	Aluminum-cast	Same
Description	Expansion control-spherical bowl	Same
Compression Height	36.5 mm (1.44 in.)	Same
Supplier	Mahle	Mahle (piston strengthened, 1993-95)

PISTON RINGS
YEARS	1990-92	1993-1995
Top Compression	Barrel-cast iron	Plated-cast iron
Middle Compression	Taper-cast iron	Lapped-cast iron
Oil Control	Cast iron-internal spring	Lapped-cast iron-internal spring
Supplier	Mahle (Goetze)	Mahle (Goetze) (design revised, 1993-95)

PISTON PIN
YEARS	1990-92	1993-1995
Material	Steel	Same
Description	Free Floating	Same
Supplier	Mahle	Mahle (design revised, 1993-95)

LUBRICATION SYSTEM
YEARS	1990-92	1993-1995
Type	Full flow. Temp regulated	Same
Main and Con Rod Bearings	Direct feed through center crank via cross drillings	Same
Cam Bearings	Forced through center cam	Same
Piston Pins	Splash	Same
Cylinder Walls	Splash	Same
Total Capacity	12 1/2 qts	Same

ACCESSORY DRIVE
YEARS	1990-92	1993-1995
Type	Single poly "V" belt	Same
Supplier	Dayco	Same

FUEL RAIL
YEARS	1990-92	1993-1995
Material	Extruded aluminum-multech injectors	Extruded aluminum-multech injectors (commonized injectors, 1993-95)
Supplier	AC Rochester	Same

INJECTOR HOUSINGS
YEARS	1990-92	1993-1995
Material	Aluminum	Same
Supplier	Dennison	Stahl (minor design change, 1993-95)

IGNITION COILS
YEARS	1990-92	1993-1995
Description	Four-direct fire	Same
Supplier	Delco	Same

ALTERNATOR
YEARS	1990-92	1993-1995
Idle Output	50 amps	Same
Max Output	120 amps	Same
Supplier	Delco	Same

VALVE TRAIN
YEARS	1990-92	1993-1995
Description	Direct acting Double overhead cam	Same

CAMSHAFT DRIVE
YEARS	1990-92	1993-1995
Description	Primary drive-silent chain- Secondary drive-duplex roller chain	Same
Supplier	Borg Warner	Same

CHAIN TENSIONERS
YEARS	1990-92	1993-1995
Description	Hydraulic	Same
Supplier	INA	Same

CAMSHAFTS
YEARS	1990-92	1993-1995
Material	Alloy cast iron	Same
Base Circle	32.8 mm (1.291 in.)	Same
Lobe Lift	9.9 mm (0.39 in.)	Same
Supplier	GM Bay City	GM Bay City (design changes, 1993-95)

STARTER MOTOR
YEARS	1990-92	1993-1995
Type	Gear reduction	Same
Output	1.4 Kw	Same
Supplier	Delco	Same

POWER STEERING PUMP
YEARS	1990-92	1993-1995
Type	Engine mounted-reservoir	Same
Supplier	Saginaw	Same

COOLING SYSTEM
YEARS	1990-92	1993-1995
Type	Pressurized	Same

RADIATOR
YEARS	1990-92	1993-1995
Core Thickness	1.34 in.	Same
Frontal Area	405 sq. in.	Same
Radiator Cap	17 psi.	Same
Thermostat Open	180 degree F	Same
Fully Open	195 degree - 200 degree F	Same

WATER PUMP
YEARS	1990-92	1993-1995
Type	Centifugal	Same
Capacity	12 gpm @ idle 85 gpm @ 7,000 rpm	Same
Supplier	Ace (Casting)	Same