1978 Pontiac Firebird Trans Am 400 CID T/A 6.6
Manual Transmission Engine Specifications

Engine Code	WC
Engine RPO	L78 w/W72
Displacement	400 CID
Bore x Stroke	4.1212" x 3.750"
Compression Ratio	8.1:1
Horsepower @ RPM	220@4000
Torque (Lb/Ft) @ RPM	320@2800
Head Casting	6X
Carburetor	4-bbl
Carburetor - Federal	17058263
Camshaft
Part #	10003402
Lift, I/E	/
Rocker Arm Ratio	1.5:1
Duration I/E - Degrees	NA / NA
Overlap - Degrees	NA
Intake Valve Dia -	2.11"
Exhaust Valve - Dia	1.66"
Distributor	1103315

1978 Pontiac Firebird Trans Am 400 CID T/A 6.6
Automatic Transmission Engine Specifications

Engine Code	X7
Engine RPO	L78 w/W72
Displacement	400 CID
Bore x Stroke	4.1212" x 3.750"
Compression Ratio	8.0:1
Horsepower @ RPM	200@4000
Torque (Lb/Ft) @ RPM	320@2800
Head Casting	4X
Carburetor	4-bbl
Carburetor - Federal	17058266
Camshaft
Part #	10003402
Lift, I/E	NA / NA
Rocker Arm Ratio	1.5:1
Duration I/E - Degrees	NA / NA
Overlap - Degrees	NA
Intake Valve Dia -	2.11"
Exhaust Valve - Dia	1.66"
Distributor	1103315