Cylinder Head - Front View

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: View Of Cylinder Head - Front

Courtesy of GENERAL MOTORS CORP.

Service Hole Location	Thread Size	Drill	Counterbore Tool	Stop Collar	Tap	Driver	Insert	Drill Depth (Max)		Tap Depth (Min)
mm	(in)	mm	(in)	-	-	-	-	-	-	-	-
1	M 10 x 1.5	211	212	N/A	213	214	14mm length	20	0.79	16	0.63
2	M 8 x 1.25	206	207	N/A	208	209	854	17	0.67	13	0.512
3	M 8 x 1.25	206	207	N/A	208	209	854	17	0.67	13	0.512
4	M 10 x 1.5	211	212	N/A	213	214	14mm length	20	0.79	16	0.63
5	M 8 x 1.25	206	207	N/A	208	209	854	17	0.67	13	0.512
6	M 8 x 1.25	206	207	N/A	208	209	854	17	0.67	13	0.512