Engine Block - Bottom View

Fig 1: Engine Block Bolt Holes - Bottom View

Courtesy of GENERAL MOTORS CORP.

Hole	Thread Size	Insert	Drill	Counterbore Tool	Tap	Driver	Drill Depth - Maximum mm (in)	Tap Depth - Maximum mm (in)
1	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
2	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
3	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
4	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
5	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
6	M16 x 1.5	-	-	-	-	-	-	-
7	N/A	-	-	-	-	-	-	-
8	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
9	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
10-11	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
12	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
13-14	M10 x 1.5	J 42385-215	J 42385-101	-	J 42385-213	J 42385-214	42.5 (1.67)	37.0 (1.45)
15	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
16	M16 x 1.5	-	-	-	-	-	-	-
17	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
18	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
19	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
20	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
21	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
22	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
23	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
24	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
25-26	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
27	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
28-29	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
30	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
31	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
32	M28 x 1.25	-	-	-	-	-	-	-
33	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
34	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	53.5 (2.10)	44.0 (1.73)
35	M10 x 2.0	J 42385-104	J 42385-101	-	J 42385-102	J 42385-103	31.0 (1.22)	25.5 (1.0)
36	M8 x 1.25	J 42385-210	J 42385-206	J 42385-207	J 42385-208	J 42385-209	22.5 (0.885)	17.5 (0.688)
Bolt holes 2, 5, 10, 11, 18, 21, 24, 28, 29, and 34 have a 20.5 mm (0.807 in) counterbore included in the 53.5 mm (2.10 in) drill depth. Bolt holes 1, 4, 9, 12, 17, 20, 23, 27, 30, and 35 have a 1.5 mm (0.059 in) counterbore included in the 31.0 mm (1.22 in) drill depth. Use sleeve J 42385-316 with the drill and tap. Bolt holes 13 and 14 have a 11.5 mm (0.452 in) counterbore included in the 42.5 mm (1.67 in) drill depth. Use sleeve J 42385-311 with the drill and tap.