1979 Models

Connect adapter between No. 1 spark plug and No. 1 spark plug wire or use an inductive type pickup. Do not puncture wires. Connect timing light according to equipment manufacturer's instructions.
Check or adjust ignition timing with engine at normal operating temperature, distributor vacuum line disconnected and plugged and shift lever in Neutral (Drive on automatic transmission equipped Light Duty vehicles).
Set timing to specifications. To adjust timing, loosen distributor hold down bolt and rotate distributor until timing is to specifications. Tighten hold down bolt, recheck timing.

NOTE: Some 1979 engines have a magnetic timing probe hole for use with special electrical testing equipment.

1975 IGNITION TIMING SPECIFICATIONS (DEGREES BTDC)

Application

Specification

350"2-Bbl.

350" 4-Bbl.

Light Duty

⁽¹⁾ 8

Heavy Duty

Federal

California

400"

Federal

California

454"

Light Duty

With Catalytic Converter

Without Catalytic Converter

Heavy Duty

455"

⁽²⁾8

⁽¹⁾	With manual transmission set to 6°BTDC.

⁽²⁾	With engine running at 1100 RPM.

1976 IGNITION TIMING SPECIFICATIONS (DEGREES BTDC)

Application

California

Federal

350" 2-bbl.

Man Trans.

.....

Auto. Trans.

.....

4-Bbl. Carb.

Light Duty

Heavy Duty

400"

454"

Light Duty

With Cat. Converter

.....

Without Cat. Converter

.....

Heavy Duty

455"

⁽¹⁾8

⁽¹⁾	With engine running at 1100 RPM.

1977 IGNITION TIMING SPECIFICATIONS (DEGREES BTDC)

Application

Man. Trans.

Auto. Trans.

305"

Light Duty

Heavy Duty

350"

Federal

California

Light Duty

Heavy Duty

High Altitude

400"

Federal

.....

California

.....

403"

Federal

.....

⁽¹⁾12

California

.....

⁽¹⁾2

454"

California

Federal

Light Duty

.....

Heavy Duty

455"

.....

⁽¹⁾	With engine running at 1100 RPM.

1978 IGNITION TIMING SPECIFICATIONS (DEGREES BTDC)

Application

Man. Trans.

Auto. Trans.

305"

Light Duty

Heavy Duty

350"

Light Duty

Heavy Duty

⁽¹⁾8

400"

Light Duty

.....

Heavy Duty

.....

454"

Light Duty

.....

Heavy Duty

⁽¹⁾	Set to 2 degrees on California models.

1979 IGNITION TIMING SPECIFICATIONS (DEGREES BTDC)

Application		Man. Trans.	Auto. Trans.
305"		6	6
350"
	Light Duty	8	8
	Heavy Duty	4	4
400"
	Light Duty	.....	4
	Heavy Duty	.....	4
454"
	Light Duty	8	8
	Heavy Duty	4	4