Need to know the year.
Go to any auto parts store and they can tell you the correct plug to buy.
Spark plug gap is 0.060
0.060
0.40
.045.
.060
.35
spark plug gap 2004 Chevy Malibu 3.5 litre
There is a placard under the hood listing the spark plug gap.
.060
,030"
0.060
The 2004 Chevy Express 6.0 liter motor spark plug gap is .032. Most spark plugs will come pre-gapped from the spark plug manufacturer.