The cylinder head casting #'s differed, but the combustion chamber was 76.18cc for both years. Pistons were flat with a notch for valve clearance at high RPM. This combination yielded a 9.0:1 compression ratio. The air cleaner was either an open element 14" round air cleaner (1973) or the dual snorkle style air cleaner (1974).
| Block | 3970010 | 4 bolt main, suffix codes: CLJ, CLK, CLL, CLM | Crankshaft | 330550 | Forged steel | Cylinder Head | 330545 | 2.02/1.6" Valves, 76.18cc, tapered spark plug, screw in studs & guide plates | Cam | 3896964 | symbol: vertical diamond, GM part # 3896962 | Intake | 3997771 | Has oil shield, EGR, Intake Runners Numbered | Carb (A/T) | 7043212 | Rochester Quadrajet 4BBL, Remote Automatic Choke, w/Automatic Trans | Carb (M/T) | 7043213 | Rochester Quadrajet 4BBL, Remote Automatic Choke, w/Manual Trans | Distributor | 1112148 | Single Point, Uniset contact, RFI shield, Vacuum, Lite Blue paint spot | RH Exhaust | 3986330 | Log type, 2.026" outlet | LH Exhaust | 3989041 | Log type, 2.026" outlet |
Water Pump: 6263701
Cylinder heads have double pyramid casting mark.
Cam specs: Hydraulic, Lift: .450/.460 (intake/exhaust), Duration: 346/360 (i/e), with 1.5 rockers.
Engine block: Nearly every 350 you'll come across is casting # 3970010, some are 2 bolt, some are
4 bolt. Some are regular, some are 010, some are 010/020 (10-20 blocks). Check the suffix code
to see what application the block is actually from. All Z28 blocks should be 4 bolt mains.
Note: Some 1973 Camaros had a 1972 external voltage regulator. This occured before February 1973.
Photo Details:
Engine Suffix & Partial VIN - 1973 Z28
Cylinder head Casting Symbol (double pyramid) |
Casting Number |
Combustion Chamber
1974 Z28 Engine - L82 245hp
| Block | 3970010 | 4 bolt main, suffix codes: CLK, CLJ, CMS, CMT | Crankshaft | 330550 | Forged steel | Cylinder Head | 333881 | 2.02/1.6, 76.18cc, identical to 333882, except w/bigger valves, screw in studs & guide plates | Cam | 3896964 | symbol: vertical diamond, Identical to 1973 | Intake | 340261 | Carb (A/T) | 7044208 | Rochester Quadrajet 4BBL, Remote Automatic Choke, w/Automatic Trans | Carb (M/T) | 7044209 | Rochester Quadrajet 4BBL, Remote Automatic Choke, w/Manual Trans | Distributor | 1112148 | Single Point, Uniset contact, RFI shield, Vacuum, Lite Blue paint spot | Distributor | 1112528 | HEI after 1/74, Vacuum, Lite Blue paint spot | RH Exhaust | 3986330 | Log type, 2.026" outlet | LH Exhaust | 3989041 | Log type, 2.026" outlet |
Water Pump: 6263701
Cam specs: Hydraulic, Lift: .450/.460 (intake/exhaust), Duration: 346/360 (i/e), with 1.5 rockers.
Distributor Note: 3123 Z28's were built after January 74 with the HEI distributor. Prior to
this the Z28 had the same distributor as the 1973 Z28.
