18436572
0.045
25-.30
The spark plug gap on 1977 Chevy truck 454 should be set at .045 inches. Spark plugs are preset at the factory and should need no adjustments prior to being installed.
Spark plugs are a cheap and quick fix if one goes out. The cost to replace one on a 454 chevy engine however can differ depending in the spark plug brand.
A 1995 Chevy Van with a 454 engine will have a spark plug gap of .060 inches. A difference of .005 (give or take) should not affect the engine's starting capabilities, however.
0.035"
A person must leave the right size gap for the spark plugs when changing them. The 1999 Chevy Suburban has a spark plug gap of .060 inches.
The number 1 plug wire on a 454 Chevy engine typically connects to the spark plug located in the front-left (driver's side) cylinder. You can refer to the firing order diagram for your specific engine to ensure the correct placement of the plug wire.
.035"
0.35
Knowing the firing order of a cars engine will help a person diagnose problems. The firing order of a Chevy 454 mark 4 is 1-3-4-2.