Engine Block - Top/Bottom Views

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

Courtesy of GENERAL MOTORS COMPANY

Hole	Thread Size	Insert	Drill	Counterbore Tool	Tap	Driver	Drill Depth - Maximum mm (in)	Tap Depth - Maximum mm (in)
J-42385-
1	M6 x 1.0	63	201	202	203	204	23.0 (0.907)	23.0 (0.907)
2	M8 x 1.25	61	206	207	208	209	29.0 (1.14)	29.0 (1.14)
3	M8 x 1.25	210	206	207	208	209	23.0 (0.907)	23.0 (0.907)
4	M10 x 2.0	104	101	N/A	102	103	30.0 (1.18)	30.0 (1.18)
5	M10 x 2.0	104	101	N/A	102	103	52.0 (2.05)	52.0 (2.05)
6	M10 x 1.5	N/A	N/A	N/A	N/A	N/A	34.0 (1.35)	34.0 (1.35)
Bolt hole 4 has a 1.5 mm (0.059 in) counterbore included in the 30.0 mm (1.18 in) drill depth. Use sleeve J-42385-316 with the drill tap. For the proper hardware and procedure, refer to Thread Repair . Bolt hole 5 has a 15.5 mm (0.807 in) counterbore included in the 52.0 mm (2.05 in) drill depth. For the proper hardware and procedure, refer to Thread Repair .