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