14

CRATE ENGINESLT4 — PART NUMBER 12371172

375 Horsepower: 6300 RPM High Tech Bullet

LT4The LT4 crate engine package is one box full of technology. Incorporating the Gen II small block design into a high reving,aluminum head small block that is suitable for carburated applications, the LT4 offers some truly cool imagery for yourstreet rod or street performance vehicle. With its cam driven water pump and high tech timing cover its got the looks thatwill get you noticed at your next car show.

The LT4 is not just about good looks since it is filled with the latest that we have to offer. For example its big valvealuminum heads with 2.00" intake and 1.55" exhaust valves, light weight hollow intake valve stems and sodium filledexhaust stems, 1.6 ratio roller rocker arms, and fast burning 54.4cc combustion chambers that yield a stout 10.8 to 1compression ratio. Unleaded premium fuel is recommended.

The LT4’s high tech parts allow it to rev to 6300 rpm, without a whimper. But we’ve incorporated a fairly mild rollercamshaft in order to offer an engine that most people can use and tune. Not surprisingly it still makes 375 horsepowerand 396 Ft. Lbs. of torque, which is plenty for most applications. If you need a little more, we’ve got you covered with ourLT4 HOT cam, available separately, and its associated timing chain and gears. The HOT cam was developed for showroom stock racing and adds over twenty horsepower and an impressive sounding exhaust note that says...line ’em up.

The LT4 crate engine package includes a fully assembled block and heads with oil pan, torsional damper and timingpointer. Also included for your installation are a dual plane aluminum intake manifold, cam driven aluminum water pump,and HEI distributor. You need only to supply a spread bore or square bore carburetor, plugs and wires, an exhaustsystem and a cool yellow ’67 Camaro convertible (just a thought.)

The LT4 is not intended for marine use, and should only be used in 1974 and earlier pre-emissions street vehicles or anyyear off road vehicles.

15

CRATE ENGINESCustomize your LT4

withGM Performance Parts

LT4 Technical InformationHorsepower .................... 375 @ 5500 RPM

Torque .......................... 396 @ 3500 RPM

Max. Recommended RPM .... 6300

Compression Ratio ............. 10.8:1

Block ............................ 10168430 Cast Iron Gen II

Crankshaft ...................... 12551485 Nodular cast iron withundercut and rolled fillets

Connecting Rods ............... 10108688 PM rods

Pistons .......................... 12551526 Hypereutectic

Piston Rings .................... 12528817

Camshaft ....................... 12551142 Hydraulic roller

Distributor ...................... 1104067 HEI

Timing Chain ................... 12555887 Single roller

Cylinder Heads ................. 12555332 Aluminum

Intake Valves ................... 12555331 Hollow stem 2.00"

Exhaust Valves ................. 12551313 Sodium filled stem 1.55"

Valve Springs................... 12551483

Rocker Arms .................... 12557779 Roller 1.6 ratio

Valve Lash ...................... Zero

Fuel ............................. 92 Octane

Technical Notes: The intake manifold, water pump, torsion damper anddistributor are included, but not installed on the engine. DistributorP/N 1104067 or melonized distributor gear P/N 10456413 must be usedon all crate engines with steel camshafts.

Below is a sample of the parts that you’ll find throughout our catalog to helpyou complete your crate engine installation or customize your crate enginefor your specific application.

24502586 — HOT Cam Hydraulic roller - Designed for showroom stockracing

12363128 — Chrome High Torque Mini Starter - High power, compactdesign

Technical Note: This starter not recommended for competition.

12361056 — GM Performance Parts Logo 8mm Spark Plug Wires

12342080 — Chevrolet Logo 14” Hi Performance Air Cleaner

24502540 — Valve Cover Adapters - Allows use of flange mount valvecovers on center bolt style heads.

12363970 — Aluminum Die Cast Valve Covers Chevrolet Logo -Require valve cover adapters 24502540

12370835 — High RPM Timing Gear Set – 1/2" Pitch, Single Roller

Service your crateengine withACDelco filtersand sparkplugs.

16

CRATE ENGINESSERVICE PARTS LIST

CHEVROLET SMALL BLOCK P/N 12371172 LT4 ENGINE KIT

17

CRATE ENGINESGM Performance Parts Custom Engine Shop

Build your own custom 350 Crate Engine KitNeed a custom 350 engine for your street rod, streetperformance car, circle tracker or drag car? With theGM Performance Parts Custom Engine Shop, you canspec out the 350 crate engine that meets your specificneeds. Simply follow the flow chart, make yourselections and record the part numbers on the final partslist located at the end of this section. Please note that thefinal parts list calls out quantities for each part. For moredetailed technical information on your selection, seeyour GM Performance Parts Authorized Center or thespecific catalog section that covers the part in question.

SHORT BLOCK

CYLINDER HEADS12356026 Cast iron head with 1.94” intakesand 1.50” exhaust valves. Used on our 350HO, this head is a good performance headto 6000 RPM and the 64cc combustionchambers yield a 9 to 1 compression ratio.

(Engine pictured uses the ZZ4 Partial Engine togetherwith components that are available throughout thiscatalog or from other sources.)

Start with a strong foundation, the ZZ4 partial engineassembly, P/N 12561723. With it’s rolled fillet nodulariron crankshaft, PM rods and high silicon pistons, theZZ4 partial engine is designed for years of highhorsepower service. The ZZ4 partial engine assemblycomes ready for a hydraulic roller cam. The four boltmain block is strong and proven in circle track anddrag racing applications. With thousands of ZZ seriescrate engines produced over the past several years,we’re sure that you’ll get more than expecteddurabilty and longevity from your ZZ4 based customengine.

Your GM Perfomance Parts Authorized Center can help you tospecify the combination of components for your application.Other components from throughout this catalog may be usedto meet your specific needs for a custom engine. Pleaseconsult with your Authorized Center or an experienced enginebuilder, prior to ordering your custom crate engine.

12556463 Aluminum head, with 1.94"intakes and 1.50" exhaust. This 58cccombustion chamber head yields a 10 to 1compression ratio and is suitable to 6000RPM. Used on ZZ4 crate engine.

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18

CRATE ENGINESGM Performance Parts Custom Engine Shop

Build your own custom 350 Crate Engine KitINTAKE MANIFOLD

10185063 Aluminumintake manifold. Mediumrise dual plane, used onZZ4 crate engine. With dualflange.

10051102 Aluminum highrise single plane manifold.Bow Tie manifold withHolley flange, for high RPMapplications.

14096011 Cast Iron highrise design, with dualflange. Patterned afteraluminum Z-28 manifold.

CAMS, ROCKER ARMSAND PUSHRODS

12495490 Stamped Steellong slot1.5 ratio rocker arms, withpivot balls and nuts.

12370838 Roller rockerarm, 1.5 ratio withhardware.

12370839 Roller rockerarm, 1.6 ratio withhardware

12371041 Push rod kit,heat treated, 2nd design

10185071 ZZ4 hydraulicroller cam

24502586 Hot Camhydraulic roller cam

12370846 Off Road dualpattern hydraulic roller cam

12371044 Roller lifter kitwith retainers, spider andbolts

See Camshaft QuickReference Chart forCamshaft specifications.

VALVE COVERS12355350 Chome shortstyle cover for center bolthead applications. Not foruse with roller rockers.

12341671 Chrome tallstyle valve cover, will clearroller rocker arms. Flangebolt.

12363970 Aluminum tallstyle valve cover for usewith roller rockerarms.Flange bolt.

24502540 AluminumCNC valve cover adapterfor use with flange boltcovers on center bolt styleheads.

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19

CRATE ENGINESGM Performance Parts Custom Engine Shop

Build your own custom 350 Crate Engine KitIGNITION

1104067 HEI Distributor

12361050 8mm Highperformance spark plugwires, with Chevrolet Bow-Tie logo and wire looms

ALTERNATORS &BRACKETS

1101641 74 Ampproduction style

10497082 94 Ampproduction style

22551517 74 Amp High-RPM racing alternator

12342020 Chromealternator brackets.

WATER PUMP12529305 Cast iron longstyle

14011012 Aluminumshort style

OIL PAN, PUMP,PICK-UP, DRIVE SHAFT,

DIPSTICK ANDWINDAGE TRAY

12528916 5 Quart pan,right hand dipstick, usedon ZZ4 crate engine

12555283 Oil pump

12550042 Oil pump pick-up tube and screen

3998287 Oil pump driveshaft

12554816 Windage tray

12551144 Dipstick

12551154 Dipstick tube

STARTER10496870 Productionstyle

12361146 High TorqueMini starter – This starter notrecommended for competition

12363128 ChromeHigh Torque Mini starter

TIMING CHAIN, GEARAND COVER

12552129 Cam timinggear

14088783 Cam timingchain

12552557 Timing coverwith pointer, plastic ZZ4style

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