1973 Pontiac Firebird Trans Am 455 CID Super Duty
Manual Transmission Engine Specifications

Engine Code	ZJ, W8
Engine RPO	LS2
Displacement	455 CID
Bore x Stroke	4.1522" x 4.121"
Compression Ratio	8.4:1
Horsepower @ RPM	290@4000
Torque (Lb/Ft) @ RPM	390@3600
Head Casting	16, 485216
Carburetor	4-bbl
Carburetor	7043273
Intake Manifold	497245, 494405, 495107
Camshaft
Part #
Lift, I/E	.410 / .410
Rocker Arm Ratio	1.5:1
Duration I/E - Degrees	301 / 313
Overlap - Degrees	76
Intake Valve Dia -	2.11"
Exhaust Valve - Dia	1.77"
Exhaust Manifolds- Right	490802
Exhaust Manifolds- Left	490803
Distributor

1973 Pontiac Firebird Trans Am 455 CID Super Duty
Automatic Transmission Engine Specifications

Engine Code	XD, Y8
Engine RPO	LS2
Displacement	455 CID
Bore x Stroke	4.1522" x 4.121"
Compression Ratio	8.4:1
Horsepower @ RPM	290@4000
Torque (Lb/Ft) @ RPM	390@3600
Head Casting	16, 485216
Carburetor	4-bbl
Carburetor	7043270
Intake Manifold	497245, 494405, 495107
Camshaft
Part #
Lift, I/E	.410 / .410
Rocker Arm Ratio	1.5:1
Duration I/E - Degrees	301 / 313
Overlap - Degrees	76
Intake Valve Dia -	2.11"
Exhaust Valve - Dia	1.77"
Exhaust Manifolds- Right	490802
Exhaust Manifolds- Left	490803
Distributor