GMC 2012 Sierra Series Owner's Manual page 531

Engine
4.3L V6 (LU3)
4.8L V8 (L20)
5.3L V8 FlexFuel with Active Fuel Management
(Iron Block) (LMG)
5.3L V8 FlexFuel with Active Fuel
Management (Aluminum Block) (LC9)
6.0L V8 FlexFuel with Active Fuel
Management (Aluminum Block)(LZ1)
6.0L V8 (Iron Block) (L96)
6.2L V8 FlexFuel (Aluminum Block) (L9H)
Engine Specifications
VIN Code
X
A
0
7
J
G
2
I n f o r ma t i o n P r o v i d e d b y :
Technical Data 12-5
Spark Plug Gap
1.52 mm (0.060 in)
1.02 mm (0.040 in)
1.02 mm (0.040 in)
1.02 mm (0.040 in)
1.02 mm (0.040 in)
1.02 mm (0.040 in)
1.02 mm (0.040 in)