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Engines
455
1974 Pontiac Firebird Trans Am 455 CID
Automatic Transmission Engine Specifications
Engine Code
AU, A4, YW, YY, Y9, ZU, ZW, Z4
Engine RPO
L75
Displacement
455 CID
Bore x Stroke
4.1522" x 4.121"
Compression Ratio
8.0:1
Horsepower @ RPM
250@4000
Torque (Lb/Ft) @ RPM
380@2800
Head Casting
4X
Carburetor
4-bbl
Carburetor - Federal
7044262
Carburetor - High Altitude
7044272
Intake Manifold
495106
Camshaft
Part #
Lift, I/E
.410 / .414
Rocker Arm Ratio
1.5:1
Duration I/E - Degrees
273 / 289
Overlap - Degrees
54
Intake Valve Dia -
2.11"
Exhaust Valve - Dia
1.66"
Distributor