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