Platinums are gapped at 0.60, and iridiums are typically gapped at 0.40... you shouldn't try to change the preset gaps.
Click the link.
Spark plug gap chevy ls blazer
.60
.60
the gap is 0.060 inches
You need a 5/8" spark plug socket.
Follow the spark plug wires, they will lead you right to them.
06.0 on a 4cylinder 2wd s10
Replace the spark plug wires, too much resistence in the old ones.
.035
40
.40 gap