I did a quick internet search using zz3 engine and got a ton of hits... here is one of the first.
This engine kit was built by GM for the Camaro. It's aluminum heads and intake, 345 horsepower, street legal high flow dual catalytic converters, dual snorkel air cleaner, computer and chip combination, make for a complete engine swap kit which should not be overlooked. This kit was created for the Camaros equipped with the 1983-86 L69 (VIN "G") or 1982-87 LG4 (VIN "H") engines.
Another -
Chevrolet engineers have developed an emission-legal conversion kit to install a High Output 5.7-liter (350ci) small-block V8 in a 1982-87 Camaro originally equipped with an LG4 or L69 305ci V8 engine and a 700R4 automatic tranmission. This coordinated package of components significantly improves vehicle performance while retaining all required emission controls.
Performance: During development of the HO 350 Camaro conversion, a prototype HO 350 engine equipped with a computer-controlled Quadrajet carburetor and all emission controls required for this application, produced 308 horsepower (at 5000 rpm) and 365 lb-ft torque (at 3500 rpm). The Chevrolet Raceshop's 1987 Camaro test vehicle equipped with an emission-legal HO 350 ran a quarter-mile elapse time of 13.83 seconds at 98 mph.
Certification: When all components are installed as specified in the instruction manual, the HO 350 conversion meets emission requirements under EPA Memorandum 1A for operation in 49 states (excluding California). The conversion is also legal for sale and use in California under California Resources Board Exemption Order #D-278. Note the entire HO 350 conversion package must be installed exactly as described in the manula to comply with emission regulations. Also note that this conversion is certified only for the specific year models, engines, and tranmission listed above.
Installation: The HO 350 conversion is designed for "do-it-yourself" installation. A comprehensive instruction manual is included. Minor welding is required to install the exhaust system. The HO 350 Camaro conversion is a coordinated package of components that work together to improve vehicle performance. Major assemblies include: Engine: The heart of the Camaro conversion is the HO 350 Chevrolet small-block V8 (P/N 24502609). High performance engine assembly has been updated with new hydraulic roller camshaft profile, a low-profile dual-pattern intake manifold, revised valvetrain components, and other improvements.
Air Cleaner: The HO 350 Camaro breathes through a dual-snorkel air cleaner. A "ram air" system channels cool air to the carburetor through flexible air ducts. Fuel Pump: A high-volume in-tank electric pump meets HO engine's fuel requirements. The pump kit includes vent lines, a sending unit, and a wiring harness. An adjustable external regulator controls fuel pressure.
Exhaust System: The HO 350 conversion package includes a low-restriction exhaust system with dual catalytic converters, high-flow exhaust manifolds with 2 1/4" outlets, a single 3" diameter tailpipe, and a transverse muffler.
Calibration: The kit includes an engine control module (ECM), specially programmed PROM chips, a coolant fan switch, an electric spark control (ESC) module, and Quadrajet secondary metering rods.