GM Service Manual Online
For 1990-2009 cars only

The purpose of New Product Information is to highlight or indicate important product changes from the previous model year.

The Northstar V8 4.6 Liter VIN Code A (RPO LH2) is new for 2004.

A Component Comparison from the Previous Year

The thread pitch on the M11 cylinder head bolts and the engine block cylinder head bolt holes has been revised for MY2004. Determine the pitch of the threads by using a thread pitch gage or measure the length of the threads of the cylinder head bolt.

*Some early MY2004 cylinder head bolts have a pitch of 1.5 mm and the length of the threads are about 48 mm (1.890 in) long.

*For most MY2004 the cylinder head bolts have a pitch of 2.0 mm and the length of the threads are about 67 mm (2.638 in) long.