1996 Chevy Lumina

Is this a 3.4 or a 3.1 Liter engine?

Spark Plug Removal And Wire Harness Routing

REMOVE OR DISCONNECT
1.Ignition Key "OFF." NOTICE: Pull on spark plug boot or heat shield only, twisting a half turn to release seal while removing. DO NOT pull on wire or spark plug lead may be damaged. CAUTION: DO NOT pry on one side of the boot with a screwdriver to remove it. The boot is made of plastic, which may break if pried with ONE screwdriver. The boot can usually be removed with your hand by twisting to loosen it, then pulling out. If the "T" is too low to allow a good grip, pliers may be used if handled CAREFULLY, or use TWO screwdrivers and apply pressure to both sides of the handle at the same time.
2.Upper Intake Manifold.
3.Spark plug wires from spark plugs.
**Note position of wires BEFORE removing.
4.Spark plug(s) from engine.
**Use spark plug socket with rubber insert to hold spark plug.

CAUTION: It is important to check the gap of all new and reconditioned spark plugs before installation. Pre-set gaps may have changed during handling. Use a round wire feeler gage to be sure of an accurate check, particularly on used plugs. Installing plugs with the wrong gap can cause pour engine performance and may even damage the engine.

Measure
Spark plug gap on plugs to be installed. Correct Gap is 1.14 mm (0.045 in.)

INSTALL OR CONNECT
CAUTION: Be sure plug threads smoothly into cylinder head and is fully seated. Use a thread chaser if necessary to clean threads in cylinder head. Cross-threading or failing to fully seat spark plug can cause overheating of plug, exhaust blow-by, or thread damage. Follow recommended torque specifications carefully. Over-or under-tightening can also cause severe damage to engine or spark plug.

1.Spark plug (AC Type R42LTSM) to engine. Tighten Spark plug(s) to 15 Nm (11 lb. ft.). CAUTION: Care should be used to avoid tearing the boot when installing it. Make sure that the boot is correctly located over the spark plug BEFORE applying pressure to seat the boot.
2.Spark plug wires.
**To proper location noted when removed.
3.Upper Intake Manifold.