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