Engine Block - Back View

Fig 1: Engine Block - Back View

Courtesy of GENERAL MOTORS CORP.

Service Call Out	Thread Size	Insert	Drill	Counterbore Tool	Tap	Driver	Drill Depth (Maximum)		Tap Depth (Maximum)		Engineering Hole Number
J 42385-							MM	(IN)	MM	(IN)	-
1	M12 x 1.75	855	856	857	858	859	39	1.535	33.5	1.32	204
2	M16 x 1.5	860	861	862	863	864	21	0.827	15	0.59	214
3	M10 x 1.5	215	211	212	213	214	29	1.161	THRU		206
4	M8 x 1.25	210	206	207	208	209	18	0.709	THRU		209
5	M8 x 1.25	854 No Flange	206	207	208	209	18	0.709	THRU		208
6	M16 x 1.5	860	861	862	863	864	21	0.827	15	0.59	213
7	M12 x 1.75	855	856	857	858	859	39	1.535	33.5	1.32	203