Engine Block - Right Side View

Fig 1: Engine Block Thread Repair Specifications - Right Side View

Courtesy of GENERAL MOTORS CORP.

Service Call Out	Thread Size	Insert	Drill	Counterbore Tool	Tap	Driver	Drill Depth (Maximum)		Tap Depth (Maximum)
J 42385-850							MM	(IN)	MM	(IN)
1	M6 x 1	205	201	202	203	204	20.5	0.807	16.5	0.65
2	M8 x 1.25	210	206	207	208	209	23.5	0.925	18	0.71
3	M8 x 1.25	210	206	207	208	209	30.5	1.201	22.5	0.89
4	M12 x 1.75	865	856	857	858	859	15.5	0.61	12.5	0.49
5	M12 x 1.75	855	856	857	858	859	33.5	1.319	26.5	1.04
6	M12 x 1.75	865	856	857	858	859	19.5	0.778	12.5	0.49