This brand new partial engine includes forged premium quality reciprocating components as well as the balancer, oil pan, flexplate and front cover. This partial engine does not include a camshaft, lifters, timing chain, or cam sprocket. Just add all the parts to complete this engine from GMPP such as cylinder heads, camshaft and valve train, intake, carburetor and ignition system. Use externally balanced flywheel for manual transmission applications.

The 454 engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the 454 engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a 454 engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a 454 engine and an older big block V8 engine. These differences may require modifications or additional components not included with the 454 engine. When installing the 454 engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a 454 engine can be installed, some procedures and recommendations may not apply to specific applications.

The 454HO engine is a fully assembled long block that also includes the intake manifold and water pump. This engine is assembled using brand new, premium quality components. The 454HO engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the 454HO engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a 454HO engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a 454HO engine and an older big block V8 engine. These differences may require modifications or additional components not included with the 454HO engine. When installing the 454HO engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a 454HO engine can be installed, some procedures and recommendations may not apply to specific applications.

Cylinder Heads

The ZZ454/440 base engine is a fully assembled long block. This engine is assembled using brand new, premium quality components. The ZZ454/440 engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the ZZ454/440 engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a ZZ454/ 440 engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a ZZ454/ 440 engine and an older big block V8 engine. These differences may require modifications or additional components not included with the ZZ454/440 engine. When installing the ZZ454/440 engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a ZZ454/440 engine can be installed, some procedures and recommendations may not apply to specific applications.

Cylinder Heads

The HT502 base engine is a fully assembled long block. This engine is assembled using brand new, premium quality components. The HT502 engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the HT502 engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to an HT502 engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between an HT502 engine and an older big block V8 engine. These differences may require modifications or additional components not included with the HT502 engine. When installing the HT502 engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which an HT502 engine can be installed, some procedures and recommendations may not apply to specific applications.

Cylinder Heads

This brand new partial engine includes forged premium quality reciprocating components as well as the balancer, oil pan and timing chain set. Just add GMPP or your custom cylinder heads, intake, carburetor and ignition system to complete. This partial engine comes with camshaft P/N 12366543 which is used in the ZZ502 and RamJet 502 engines. The camshaft must be changed to P/N 12552296 to match the HT502 specifications or P/N 24502611 to match the 502 HO specifications.

The 502 engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the 502 engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a 502 engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a 502 engine and an older big block V8 engine. These differences may require modifications or additional components not included with the 502 engine. When installing the 502 engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a 502 engine can be installed, some procedures and recommendations may not apply to specific applications.

The 502HO engine is a fully assembled long block that also includes the intake manifold and water pump. This engine is assembled using brand new, premium quality components. The 502HO engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the 502HO engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a 502HO engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a 502HO engine and an older big block V8 engine. These differences may require modifications or additional components not included with the 502HO engine. When installing the 502HO engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a 502HO engine can be installed, some procedures and recommendations may not apply to specific applications.

Cylinder Heads

The 502/502 base engine is a fully assembled long block. The ZZ502 and RamJet 502 Crate engines share the same part number long block (base engine). This engine is assembled using brand new, premium quality components. The 502/502 engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the 502/502 engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a 502/502 engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a 502/502 engine and an older big block V8 engine. These differences may require modifications or additional components not included with the 502/502 engine. When installing the 502/502 engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a 502/502 engine can be installed, some procedures and recommendations may not apply to specific applications.

Cylinder Heads

The ZZ502 deluxe engine assembly includes additional components to the long block assembly which make up the deluxe engine. Additional key items include the intake manifold, carburetor, distributor, and the water pump. The ZZ502 deluxe engine is a fully assembled engine. This engine is assembled using brand new, premium quality components. The ZZ502 deluxe engine is manufactured on current production tooling; consequently you may encounter dissimilarities between the ZZ502 deluxe engine assembly and previous versions of the big block V8. In general, items such as motor mounts, accessory drives, exhaust manifolds, etc. can be transferred to a ZZ502 deluxe engine when installed in a vehicle originally equipped with a big block V8 engine. However, as noted in the following sections, there may be significant differences in the water pump, torsional damper, etc., between a ZZ502 deluxe engine and an older big block V8 engine. These differences may require modifications or additional components not included with the ZZ502 deluxe engine. When installing the ZZ502 deluxe engine in a vehicle not originally equipped with a big block V8, it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, and exhaust systems. Due to the wide variety of vehicles in which a ZZ502 deluxe engine can be installed, some procedures and recommendations may not apply to specific applications.

Ignition System

Water Pump

The ZZ502 deluxe engine comes with an aluminum, short style water pump, GM Part Number 14058915. The pump included with this kit has a standard rotation impeller that is used with conventional accessory drives. Some serpentine belt systems require a water pump with a reverse-rotation impeller. In these instances, install a water pump specified for the original application.

Timing Information

Set initial spark timing at 10° before top dead center (BTDC) at 650 rpm with the vacuum advance line to the distributor disconnected and plugged. This setting will produce 32° of total advance at wide-open throttle (WOT). The HEI vacuum advance canister should remain disconnected. This engine is designed to operate using only the internal centrifugal advance to achieve the correct timing curve. The HEI distributor supplied with the ZZ502 deluxe engine has mechanical centrifugal spark advance with the following curves:

Carburetor

The carburetor included with the ZZ502 deluxe engine is a Holley 4-barrel Model 4150 dual feed fuel inlet, vacuum secondary carburetor. This carburetor features center hung float bowls, electric choke, power valve blow-out protection, and a secondary power valve. It has the correct calibration for ZZ502 crate engines. For more information and carburetor set up instructions, see the specific carburetor instruction sheet or visit www.holley.com.

Air Cleaner

The ZZ502 deluxe engine does not include an air cleaner assembly. GM Part Number 12342080, is a chrome, 14 inch, low profile air cleaner assembly with CHEVROLET on its cover. This part number is supplied with a 3 inch tall air cleaner element, GM Part Number 6421746. A taller 4 inch air cleaner element is available as GM Part Number 8997189.

The ZZ572 deluxe engine assembly includes additional components to the long block assembly which make up the deluxe engine. Additional key items include the intake manifold, carburetor, distributor, and the water pump.

GM recommends that you use a minimum octane rating of 92 (R+M/2) fuel in the ZZ572/620 (9.6:1 compression ratio) and 110 octane fuel in the ZZ572/720R (12:1 compression ratio) to prevent preignition.

Ignition System

Flex Plate/Pilot Bearing

Indicator Tube

The indicator and indicator tube come installed on the engine. One end is pushed into the hole on the oil pan and sealed with an o-ring. The other end is fastened to the block using a bolt and a spacer. When removing the dipstick to install the engine or headers, be sure not to loose the small o-ring which seals the dipstick tube to the pan. The o-ring must be reinstalled on the dipstick tube before inserting it into the pan. Make sure the tube is bottomed out in the pan before tightening the dipstick tube to the header bolt. Also, the spacer and fastener that were attaching the dipstick tube to the engine will not be required once the headers are installed. They were for shipping purposes only.

Carburetor

Please refer to the documentation supplied with the carburetor for installation and tuning instructions. If you have technical questions regarding the carburetor or cannot locate the instructions, please contact the carburetor manufacturer at (706) 864-8544. The air cleaner size should be at least 14.0" in diameter and 4.0" tall or with equivalent surface area to allow adequate air flow to the engine.

Exhaust Header Information

The engines were developed using 2.25" diameter x 36" long primary tube headers with 3.50" diameter collectors.

The ZZ572 long block assembly includes additional components to the short block assembly which make up the long block. Some key items included are the aluminum cylinder heads, valve train, camshaft, lifters, SFI Foundation Inc. approved harmonic damper, and oil pan. Specific items and part numbers are listed at the end of these instructions.

GM recommends that you use a minimum octane rating of 92 (R+M/2) fuel in the ZZ572/620 (9.6:1 compression ratio) and 110 octane fuel in the ZZ572/720R (12:1 compression ratio) to prevent preignition.

Cylinder Head Installation

Installation is the same as for original equipment cylinder heads with the exception of two additional cylinder head bolts located inside the lifter valley as noted below. Be sure to thoroughly clean the surface of the block and the surface of the cylinder head prior to installing. Apply Moly-lube thread lubricant to all head bolt threads. Apply liquid Teflon to the valley head bolts that protrude into the intake runners. Tighten the bolts alternately per the sequence and pattern shown below. Apply torque in 25 ft.lb. increments over two repetitions with the third repetition to the final tightening specification. A re-torque of the cylinder head bolts is recommended after heat cycling the engine.

The ZZ572 short block assembly incorporates modern technology in a package that can be installed in applications where 366cid and larger displacement Big Block Chevrolet (BBC) V-8s were originally used. This short block is assembled using brand new, premium quality components. Due to the wide variety of applications in which a ZZ572 short block assembly can be used, some procedures and recommendations may not apply to specific applications.

The ZZ572 short block assembly in an all new Gen VI Tall Deck Bow Tie Cylinder Block manufactured on new production tooling; consequently you may encounter dissimilarities between the ZZ572 tall deck BBC short block assembly and previous versions of the BBC V-8. In particular is the fact that the ZZ572 tall deck BBC short block assembly in a "Tall Deck", meaning the distance from the crankshaft centerline measured perpendicular to the deck surface is 10.2" or .400" greater than a "Short Deck" BBC (9.8"). This increase may cause interference in some applications where a short deck BBC was previously installed. Also, the ZZ572 engines are internally balanced and only should be used with internally balanced flywheel, flexplates, and harmonic dampers. In general, items such as motor mounts, bell housing, starters, etc. can be transferred to this ZZ572 tall deck BBC short block assembly when it is installed in a vehicle originally equipped with a BBC V-8 engine. However, such items as intake manifolds, headers, push rods, etc. are different. These differences may require modifications or additional components not included with this ZZ572 tall deck BBC short block assembly. When installing a ZZ572 tall deck BBC short block assembly in a vehicle not originally equipped with a BBC V-8 it may be necessary to adapt or fabricate various components for the cooling, fuel, electrical, accessory drive system and exhaust systems.

Starter

The starter recommended by GM is a high-torque mini starter. It is a compact starter that delivers plenty of torque in a small package which offers increased clearance for extended oil pans and exhaust systems. It is available either black, GM part number 12361146, or chrome, GM part number 12363128.

The ZZ572 deluxe engine assembly includes additional components to the long block assembly which make up the deluxe engine. Additional key items include the intake manifold, carburetor, distributor, and the water pump. GM recommends that you use a minimum octane rating of 92 (R+M/2) fuel in the ZZ572/620 (9.6:1 compression ratio) and 110 octane fuel in the ZZ572/720R (12:1 compression ratio) to prevent preignition.

Ignition System

Timing Information For Both Engines

Set spark timing at 36° BTDC at 4000 RPM with the vacuum advance line to the distributor disconnected and plugged. This setting will produce 36° of total advance at wide open throttle. The HEI vacuum advance canister should remain disconnected.

Flexplate and Pilot Bearing

Indicator Tube

The indicator and indicator tube come installed on the engine. One end is pushed into the hole on the oil pan and sealed with an o-ring. The other end is fastened to the block using a bolt and a spacer. When removing the dipstick to install the engine or headers, be sure not to loose the small o-ring which seals the dipstick tube to the pan. The o-ring must be reinstalled on the dipstick tube before inserting it into the pan. Make sure the tube is bottomed out in the pan before tightening the dipstick tube to the header bolt. Also, the spacer and fastener that were attaching the dipstick tube to the engine will not be required once the headers are installed. They were for shipping purposes only.

Carburetor

Please refer to the documentation supplied with the carburetor for installation and tuning instructions. If you have technical questions regarding the carburetor or cannot locate the instructions, please contact the carburetor manufacturer at (706) 864-8544. The air cleaner size should be at least 14.0" in diameter and 4.0" tall or with equivalent surface area to allow adequate air flow to the engine.

Exhaust Header Information

The engines were developed using 2.25" diameter x 36" long primary tube headers with 3.50" diameter collectors.