PONTIAC, Tempest, Firebird

350" V8	2GV	7028071	7029062
40C" V8	2GV	7028066	7029060

CHANGES, CAUTIONS, CORRECTIONS 

• C.C.S." & "A.I.R." ENGINES NOTE:  These engines have special exhaust emission controls as follows: Specially calibrated distributors and carburetors, closed positive crankcase ventilation system, and related control units. C.C.S. Engines  - Have "thermo air cleaner" (vacuum powered, thermostatically controlled cleaner air intake for control of carburetor air temperature). A.I.R. Engines (Chevrolet Synchro-mesh)  - Air pump used for air injection in engine at exhaust valve ports.
• 1968 TEMPEST & FIREBIRD 350" V8 & 400" GTO V8, & PONTIAC 400" V8 CORRECTION FOR IRREGULAR EXHAUST NOISE, ROUGH IDLE OR DOWNSHIFT CLUNK ON 2-SPEED AUTOMATIC TRANSMISSIONS (Automatic Trans. Cars Before 10/10/67):  Production change listed below for these engines will eliminate this complaint on later cars. Rework vacuum system and change idle speed setting as follows:

1. Remove yellow-stripe hose from carburetor port to TVS and vacuum hose from TVS to retard port on distributor vacuum unit and discard these hoses (do not remove steel hose fittings from TVS). Cap these two fittings using No. 9781338 Caps or connect tubes with short piece of discarded hose to exclude foreign particles from TVS. Cap open port on carburetor with same type cap but DO NOT cap port on distributor vacuum unit. Check and adjust ignition timing.
2. Set idle speed to revised increased RPM: Solenoid Active Idle Speed in Drive  - 650 RPM (was 600 RPM), Solenoid Inactive Idle Speed  - 575 RPM (Was 500 RPM).

• 1968 TEMPEST & FIREBIRD 350" V8 & 400" GTO V8, & PONTIAC 400" V8 SPARK RETARD & IDLE SPEED PRODUCTION CHANGE (Engines with Automatic Transmission Only):  At approximately 10/10/67, the following changes were made to improve idle, reduce exhaust noise, and eliminate downshift clunk on two-speed automatic transmissions:

1. Vacuum hoses from carburetor port below throttle valves to TVS and from TVS to retard side of distributor vacuum unit were eliminated (this eliminates timing retard action at idle).
2. Engine idle speed was increased as follows: Solenoid Active Idle Speed in Drive  - 650 RPM (was 600 RPM), Solenoid Inactive Idle Speed  - 575 RPM (was 500 RPM).
   NOTE: Revised engines will have new decal listing these revised idle speeds.

• 1968 PONTIAC & TEMPEST V8 ENGINES IDLE STOP SOLENOID BRACKET MISPOSITION CORRECTION:  If idle stopscrew cannot be adjusted out sufficiently for correct "solenoid active" idle speed setting, loosen left front carburetor-to-manifold nut, position solenoid bracket properly and hold bracket in this position while tightening nut to 15 ft. lbs. torque.