Exhaust Manifold Installation - Left Side (LS7, LS9)

Fig 1: View Of Left Exhaust Manifold, Gasket & Bolts

Courtesy of GENERAL MOTORS CORP.

CAUTION: Refer to Fastener Caution .

NOTE:

Tighten the exhaust manifold bolt as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or on-board diagnostic (OBD) II system performance.
The cylinder head exhaust manifold bolt hole threads must be clean and free of debris or threadlocking material.
Do not apply sealant to the first 3 threads of the bolts.

Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 10953488), or equivalent, to the threads of the exhaust manifold bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers .
Install the exhaust manifold (2), NEW gasket (3), and bolts (1) and:
1. Tighten the exhaust manifold bolts a first pass to 15 N.m (11 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, working toward the outside bolts.
2. Tighten the exhaust manifold bolts a final pass to 20 N.m (15 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, working toward the outside bolts.
Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.