Chevrolet - GM AND CHEVROLET BIG-BLOCK CYLINDER HEADS
     This page list the brand new GM, GMPP, and Chevrolet big-block cylinder heads that are in the GMPP catalog and more. Some have been discontinued but we still show them for information purposes and we may add some that were never shown in their catalog because we feel they should have been shown. There are some that we show here that GM took out of their catalog just to make room for something else but we will still continue to show it.
     Keys - gmhead, gmheadpart
 WEB SITE NAVIGATION INFORMATION
     If you have you just came from a search engine and are stuck with no navigation, turn on Java Scripts in your Web browser, reload the page, then you can turn off Java Scripts again. Also, people using Internet Explorer have to use the pull down tab next to the back button to return to a search engine. More information on this is on our help page.
     GM and Chevrolet part prices are in the Price & Parts search. Keys are to be used with the Price & Parts Search. Enter a Key, part number, GM, SC, or a key word, like 502, into the Price & Parts search to see if we have it on our site. Use GM for a list of both GM and GMPP parts. Use SC for a list of all Chevrolet exclusive parts. Aftermarket company prices are on downloadable Price Sheets or on their pages. The Page Search is for searching the pages of our Web site. More information on this is on our help page.

 CYLINDER HEAD NAVIGATION
GM Cylinder Head Index GM 4 & 6 Cylinder Heads GM Small-Block Heads GM Big-Block Heads
GM Cylinder Head Parts GMPP SB Reference Chart GMPP BB Reference Chart GM L31 350 Vortec Head
GM Fast Burn 350 Heads GM 350 Swirl Port Head    

 GM BIG-BLOCK CYLINDER HEADS IMPORTANT TECHNICAL NOTE
     Use of the adjustable Mark IV cylinder head is not recommended with the new “Gen V engine”. Changes in the configuration of the “Gen V’s coolant transfer passages allows coolant to seep into the lifter valley when the Mark IV head is used. All Gen VI blocks will accept Mark IV cylinder heads because the water coolant holes were decreased in size. These cylinder cases all have aluminum front cover with six bolts, not the sheet metal front cover. Mark IV camshafts, water pumps, intake manifolds, distributor, and clutch housings can be used with the new “Gen V” engines.

 GM BIG-BLOCK CYLINDER HEADS
Chevrolet carries both GM and GMPP cylinder heads.
Chevrolet also carries a number of other Aftermarket company heads like Edelbrock and World Castings.
     Some heads have “(Pic)” under the Link column. This indicates that there is a picture that you can see for that head. If you click on (Pic) you will see it and a separate page will open showing you the picture. You can either leave this window open and go back and forth between the two windows or you can close the window with the picture and you will still have this window open. If you see (Page) under the Link column, it works the same way that (Pic) does except you will see a page that is just for this head instead of only a picture.
If you don’t see what you are looking for, call us and ask about it, using our toll free 1-800 number.
All GM cylinder heads are sold as a single head with one head per box. The prices for these are for a single head.
Part # Description Link
06260482 BBC Mark IV Cast Iron, Open Chamber, Rectangular Port, 1968-90.
     This is Chevrolet’s best cast iron cylinder head for high-performance big-block V8s. It offers exceptional power at an economical price. This casting has 118cc open combustion chambers that reduce shrouding at high valve lift and improve engine airflow. The seats are ground for large 2.19” diameter intake valves and 1.88” exhausts. This high-performance head has rectangular intake ports and square exhaust ports. It is machined for 7/16” screw-in studs and guideplates (not supplied).
Technical Notes: (see “Technical Notes” at the beginning of the Cylinder Head Group section for important information) This head was installed on LS-6 engine assembly P/N 366250 and LS-7 engine assembly P/N 3965774. It can be used with both closed and open chamber pistons to produce various compression ratios. Casting number 14096188 or 6272990. Can not be used on Gen V engines because of upper water hole alignment. Open Chamber Design. [ Discontinued ] No longer available from GM.		 (Pic)
10045427 BBC Pontiac Super Duty Head, Large Port 1965-90.
      Pontiac Motorsports’ aluminum cylinder heads for big-block V8s have high-flow 460cc intake runners which are raised and relocated to enhance airflow. This head is designed for Pro Stock and similar all-out racing engines which range in displacement from 450 to 600 cubic inches. Its advanced runner design eliminates the need for extensive porting to achieve maximum performance. The “long” and “short” intake ports are relocated to equalize runner volumes to within one percent. The minimum wall thickness of .450” allows major modifications without welding. The D-shaped exhaust runners have a port volume of 145cc’s. The Super Duty head’s intake valve angle is 18° , and the exhaust valve angle is 9°. This represents an 8° “roll” compared to a production big-block V8 head. The ductile iron seats installed in the 91cc combustion chambers will accept 2.40” diameter intake valves and 1.90” exhaust valves. The Pontiac Super Duty head uses 3/4” reach gasketed plugs. It is cast iron from A-356.2 alloy aluminum.
Technical Notes: Use of the adjustable Mark IV cylinder head is not recommended with the new Gen V engine”. Changes in the configuration of the “Gen V’s” coolant transfer passages allows coolant to seep into the lifter valley when the Mark IV head is used. Mark IV camshafts, water pumps, intake manifold, distributor and clutch housings can be used with the new “Gen V” engines. A water manifold should be fabricated by the customer from braided steel hose to equalize the cylinder head temperatures and eliminate water flow through the intake manifold. Phosphorous bronze valve guides are supplied but not installed. This head requires extra-long valves and special aftermarket valvetrain components. Intake runners in production-type manifolds will not align with the relocated ports in this cylinder head casting. Use Pontiac cast aluminum valve covers P/N 12341643 (two per set).		 (Pic)
10051128 BBC Symmetrical Port Bow Tie Head 1965-90.
      Symmetrical port aluminum big-block cylinder heads are designed for Pro Stock drag racing and similar maximum-effort competition applications. This head has four equally spaced, symmetrical intake runners which equalize the airflow between the cylinders. Threaded plugs in the roofs of two runners provide access to socket head capscrews which are used in place of two head bolts. The intake runners are raised .950” above the stock position to provide a direct “line of sight” path to the combustion chambers. The minimum port wall thickness is .240”. The round exhaust runners are 1.150” higher than the production port location. The symmetrical port head is .625” taller than Bow Tie head P/N 14044862. The symmetrical port Bow Tie cylinder head’s valve angles are revised to increase valve clearance and reduce shrouding. The intake valve angle is 180 (versus 260 in production heads), and the exhaust valve angle is 100 (vs. 170). The compound angle of both valves is reduced from 40 to 2.50. The symmetrical port head has shallow 72cc combustion chambers with centrally located spark plugs.
Technical Notes: Use of the adjustable Mark IV cylinder head is not recommended with the new “Gen V engine”. Changes in the configuration of the “Gen V’s” coolant transfer passages allows coolant to seep into the lifter valley when the Mark IV head is used. Mark IV camshafts, water pumps, intake manifold, distributor and clutch housings can be used with the new “Gen V” engines. The symmetrical port cylinder head is sold without seats and guides. Its raised ports and deep valve bowls require valves which are .800” longer than production valves. This head requires a fabricated intake manifold, aftermarket rocker arms, aftermarket studs or head bolts, and special pistons. Chevrolet Bow Tie rocker covers can be installed on symmetrical port cylinder heads.		 (Pic)
10051129 BBC Unmachined Symmetrical Port Cylinder Head 1965-90.
      This unmachined casting of the Bow Tie symmetrical port head is intended for cylinder head specialists and competition engine builders who want to make extensive modifications. The Aluminum alloy specified for this raw cylinder head makes the casting slightly harder and easier to weld than a fully machined version.
Technical Notes: Use of the adjustable Mark IV cylinder head is not recommended with the new “Gen V engine”. Changes in the configuration of the “Gen V’s” coolant transfer passages allows coolant to seep into the lifter valley when the Mark IV head is used. Mark IV camshafts, water pumps, intake manifold, distributor and clutch housings can be used with the new “Gen V” engines. Raw symmetrical port heads are cast from 355-T6 aluminum. The intake runners in raw castings are slightly smaller than the ports in finished heads.		 --
10093385 BBC Pontiac Aluminum Head 1965-90 Mark IV.
      This aluminum cylinder head is designed for the Chevrolet Big-Block engine and bears a Pontiac logo. It is a “raw” (unmachined) head with 15° valve angles with spread intake runners. Use on Mark IV blocks only.		 (Pic)
10093386 BBC Pontiac Aluminum Head 1965-90.
      This big block aluminum cylinder head developed by Pontiac is fully machined and has 15° valve angles with spread port intake runners. It is for use with all Chevrolet Big-Block engines. Use on Mark IV blocks only.
Technical Notes: Intake manifold must be fabricated; use a Fel-Pro gasket.		 (Pic)
10140633 BBC Mark IV Cast Iron Closed Chamber Rectangular Intake Port Head.
      This high-performance cast iron cylinder head has rectangular intake ports, square exhaust ports, and 108cc closed combustion chambers. It is machined for 2.19” diameter intake valves and 1.72” diameter exhaust valves. The rocker arm stud bosses are drilled and tapped for 7/16” screw-in studs (not supplied). This head was originally installed on 1965-69 special high-performance big-blocks. (Discontinued)
Technical Notes: Do not use with open chamber pistons.		 (Pic)
12363390 BBC Complete Oval Port Aluminum Head, 2.25“/1.88” Valves.
      This head is identical to P/N 12363399, except it has 2.25” stainless steel intake valves, and 1.88” stainless steel exhaust valves with 11/32 stems. It also includes high performance valve springs, valve spring caps, keys and valve stem seals. These heads are designed for high horsepower 396, 427, 454, and 502 engines.
Technical Notes: For 502ci engines, use head gasket kit P/N 12363411 and no sealant on the head bolt. For all big-block engines, use intake manifold gasket kit P/N 12366985, with intake bolt kit P/N 12367959, and cylinder head bolt kit P/N 12367779. Use the following components for service: P/N 12366987 Intake Valve 2.25”; P/N 1366988 Exhaust Valve 1.88”; P/N 12462970 Valve Spring; P/N 12366990 Valve Spring Retainer; P/N 3875916 Valve Spring Shim (Requires 2); P/N 12366992 Valve Lock; P/N 12366993 Oil Seal.		 (Pic)
12363392 BBC Complete Oval Port Aluminum Head, 2.19”/1.88” Valves.
      This head is identical to P/N 12363399, except it has 2.19” stainless steel intake valves, and 1.88” stainless steel exhaust valves with 11/32 stems. It also includes high performance valve springs, valve spring caps, keys and valve stem seals. These heads are designed for 396, 427, 454, and 502 engines.
Technical Notes: For 502ci engines, use head gasket kit P/N 12363411 and no sealant on the head bolt. For all big-block engines, use intake manifold gasket kit P/N 12366985, with intake bolt kit 12367959, and cylinder head bolt kit P/N 12367779. Use the following components for service: P/N 12366986 Intake Valve 2.19”; P/N 12366988 Exhaust Valve 1.88”; P/N 12462970 Valve Spring; P/N 12366990 Valve Spring Retainer; P/N 3875916 Valve Spring Shim (Requires 2); P/N 12366992 Valve Lock; P/N 12366993 Oil Seal.		 (Pic)
12363399 BBC Signature Series Aluminum “Oval Port” Cylinder Head.
      Signature Series Aluminum “Oval Port” Cylinder Head. These oval port cylinder head will fit all 1965-1996 Mark IV and Gen V or VI 396 thorough 502 cubic inch big block Chevrolet engines. They are fully machined with semi-finished Bronze Alloy guides and semi-finished valve seats that use 2.19/1.88” valves. These high velocity 290cc intake runners enhance mid range throttle response and torque. The exhaust runner volume is 110cc., the 110cc semi open combustion chamber design will make a very streetable compression ratio. Spring DIA is 1.55”, with 7/16” rocker stud holes. These accept all stock accessory brackets except Gen V where the bracket holes have been enlarged to 7/16”. The roller studs and exhaust bolt holes are heli-coiled for strength.
Technical Notes: These heads are made from A356-T6 aluminum alloy. The 9/16” deck surface is for maximum strength and greater head gasket sealing. Designed for 3/8” push rod diameter. These heads require cylinder head bolt kit P/N 12367779. Use the following performance head gasket 1965-90 with standard bore to 4.370” use P/N 12363414 and with 4.47” to 4.540” use P/N 12363413, and with GEN V 1991-98 engines with standard to 4.370” use P/N 12363412, with bores of 4.47” to 4.54” use gasket P/N 12363411. The semi-finished bronze guide can be finished either 11/32” or 3/8”. The inter-locking hardened valve seat will accept leaded or unleaded gas. Use intake gasket P/N 12366985.		 (Pic)
12363400 BBC Complete Rectangular Port Aluminum Head, 2.25”/1.88” Valves.
      This head is identical to P/N 12363410, except it has 2.25” stainless steel intake valves, and 1.88” stainless steel exhaust valves with 11/3” stems. It also includes high performance valve springs, valve spring caps, keys and valve stem seals. These heads are designed for high horsepower 396, 427, 454, and 502 engines.
Technical Notes: For 502ci engines, use no sealant on the head bolts. For all big-block engines, use intake manifold gasket kit P/N 12366985, with intake bolt kit P/N 12367959, and cylinder head bolt kit P/N 12367779. Use the following components for service: P/N 12366987 Intake Valve 2.25”; P/N 12366988 Exhaust Valve 1.88”; P/N 12492970 Valve Spring; P/N 12366990 Valve Spring Retainer; P/N 3875916 Valve Spring Shim (Requires 2); P/N 12366992 Valve Lock; P/N 12366993 Oil Seal.		 (Pic)
12363408 BBC NHRA Legal Aluminum Bare Head, 2.19”/1.88” Valves.
      This new aluminum cylinder head is a replacement for the 1969 L88 head P/N 14011076 used on 1969 Camaro and 1968-71 Corvette vehicles and is legal for use in NHRA racing. This head is similar to P/N 12363410 except that the intake ports are as cast (no CNC machining). The valve seats can be machined to 2.19” intake and 1.88” exhaust or larger. The rectangular port intake volume is 315cc, with square exhaust ports. The combustion chamber is 118cc and the valve guides start at 11/32”, but can be machined to 11/32” or 3/8” valve stem hole.
Technical Notes: The casting is P/N 12363401. This head is sold as bare head only.		 (Pic)
12363410 BBC Aluminum Rectangular Port Head, Signature Series.
      This Cylinder head fits all 1965-1996 Mark IV and GEN V and VI 396 thru 502 cubic inch Big Block Chevrolet engines. They are fully machined with semi-finished bronze alloy guides and semi-finished valve seats that use 2.19/1.88” valves. These high velocity 315cc long intake runner and 300cc short runners enhance mid-range throttle response and torque. The exhaust runner volume is 110cc. The 118cc semi-open combustion chamber design will make a very streetable compression ratio. Spring DIA is 1.55”, with 7/16” rocker stud holes. These accept all stock accessory brackets except GEN V where the bracket holes have been enlarged to 7/16”. The rocker studs and exhaust bolt holes are heli-coiled for strength. Intake and exhaust ports are in stock locations.
Technical Notes: These heads are made from A356-T6 aluminum alloy. The 9/16” deck surface is for maximum strength and great head gasket sealing. Designed for 3/8” push rod diameter. These heads require cylinder head bolt kit P/N12367779. Use the following performance head gasket 1965-1990 with standard bore to 4.370” use P/N 12363414 and with 4.47” to 4.540” use P/N 12363413, and with Gen 1991-1996 engines with standard to 4.370” use P/N 12363412, with bores of 4.47” to 4.54” use gasket P/N 12363411. The semi-finished bronze guide can be finished either 11/32” or 3/8”. The interlocking hardened valve seat will accept leaded or unleaded gas. Use intake gasket P/N 12511789.		 (Pic)
12363425 BBC Signature Series Racing Bow Tie Cylinder Head 1965-96, Aluminum, Raised Port.
      This aluminum Bow Tie cylinder head offers a significant performance improvement over production castings. Bow Tie heads are recommended for large displacement competition engines 1965-1996 Mark IV, Gen V and Gen VI. The Bow Tie head’s intake runners are raised .100” above the standard port location and enlarged to improve airflow. The rectangular exhaust ports are raised .750” from the standard position to reduce turbulence in the runners. Vanes in the floor of the exhaust ports reduce turbulence (these are referred to as “W” ports by some Chevrolet enthusiasts). The big-block Bow Tie head has unique 115cc open combustion chambers. Material was added between the valve seats to reduce the combustion chamber volume, and the chamber walls adjacent to the valves are not relieved. The seat inserts and bronze valve guides are semi-finished for 2.19” diameter intake valves and 1.88” exhaust valves. The rocker arm stud bosses are reinforced and heli-coiled to improve reliability with racing valve springs. The rocker cover rails are raised .250”; standard valve covers can be installed. Two additional head bolt holes are drilled in valley area.
Technical Notes: The Bow Tie cylinder head’s raised intake runners require valves which are .400” longer then the stock. The valve spring seats can be machined .200”; check the valve spring installed height after machining the spring pads. Pushrod guideplates (P/N 3860038) must be ground for clearance before installation. The upper intake manifold bolt holes are not drilled in Bow Tie cylinder heads. Ports in production and after market intake manifolds must be modified to match the intake runner entrances. This head’s exhaust flange bolt holes are in the standard big-block location; drill and tap new bolt holes in the exhaust manifold flange or modify the header flanges to center the exhaust pipes over the port exits the deck thickness is 9/16” for maximum strength. The four head bolt bosses adjacent to the exhaust ports are taller than production heads: for 3.38” use 4.19” bolt(6)or 4.50” bolt(2); for 4.69” use 5.50” bolt(4); for 1.38” use 2.19” bolt(4). The heads are cast from A356-T6 material and the casting P/N is 14044861, same as the first design heads.		 (Pic)
12480010 BBC DRCE Racing Head Semi-Finished.
      This new DRCE semi-finished head is for the new 4.900” bore center blocks. It is the same as P/N 24502585 except it is a semi-finished “cubed” head. For raw casting see P/N 234502585. [New P/N 25534405]		 (Pic)
25534405 BBC DRCE Racing Head Semi-Finished.
      This new DRCE semi-finished head is for the new 4.900” bore center blocks. It is the same as P/N 24502585 except it is a semi-finished “cubed” head. For raw casting see P/N 234502585. [Old P/N 12480010]		 (Pic)
12562917 BBC Complete Head, Service Replacement Cast Iron.
      Round intake port, square exhaust port, 2.07”/1.72” valves, Open combustion chamber 118cc. Casting number 10114156. Use with Gen VI big-block engine P/N 12360893. Head comes with valves and springs. [Old P/N 12552888]		 --
12562920 BBC Complete Gen V & Gen VI Cylinder Head, Cast Iron
      Open Chamber, 2.19”/1.88” Valves. These are the same as 14096802 except they include the valves, springs and caps. For 1991 and later Gen V & Gen VI engines.
These heads include the following: a 118cc open chamber, rectangular intake ports design, and 3/8” rocker stud holes. These heads are designed to use net lash or non-adjustable rocker arms, and have 7/16-14 accessory holes in the ends of the head. Casting number is 14097088. (Complete Single) [Old P/N 14096801]
Technical Notes: Use the following components for service: Intake valves 2.19” P/N 14097045, Exhaust valves 1.88” P/N 14097049, Valve spring P/N 14097002, Valve spring cap & seal kit P/N 12360874, Valve stem key P/N 03947880, Valve spring shim P/N 03875916.		 (Pic)
12562925 BBC Bare Gen V & Gen VI Cylinder Head, Cast Iron
      Open Chamber, 2.19”/1.88” Valves. This “Gen V & VI” iron cylinder head is used on high performance 454 and 502 off road engines from 1990-2000. This is a bare head and requires 2.18” intake and 1.88” exhaust valves with 7/16” stems. No valves or springs included in this head. These heads include the following: 118cc open chamber, rectangular intake ports design, and 3/8” rocker stud holes. These heads are designed to use net lash or non-adjustable rocker arms and have 7/16-14 accessory holes in the ends of the heads. (Bare Single) [Old P/N 10191660]		 --
12562926 BBC Bare Gen V & Gen VI Cylinder Head, Cast Iron
      Open Chamber, 2.19”/1.88” Valves. This “Iron” cylinder head is intended for use with the Gen V & Gen Vi design 454 (7.4-liter) big-block HO V8 engine (P/N 24502618) and 502 engine (P/N 24502620). The heads are 118cc open chamber with 2.19” intake valves and 1.88” exhaust valves with rectangular intake ports. They have 3/8” rocker bolt holes. Casting number is 14097088. (Bare Single) [Old P/N 14096802]		 --
14044876 BBC Raw Casting Head (Not Machined).
      This raw casting was used to make first design cylinder head assembly 14044861 or 14044862. This casting has no machining on it.		 --
14096801 BBC Complete Gen V & Gen VI Cylinder Head, Cast Iron
      Open Chamber, 2.19”/1.88” Valves. These are the same as 14096802 except they include the valves, springs and caps. For 1991 and later Gen V & Gen VI engines.
Technical Notes: These are “Iron” heads with rectangular intake ports. (Complete Single) [New P/N 12562920]		 (Pic)
14096802 BBC Bare Gen V & Gen VI Cast Iron Head, Rectangular Intake Ports, 1991-92.
      Open Chamber, 2.19”/1.88” Valves. This “Iron” cylinder head is intended for use with the Gen V & Gen Vi design 454 (7.4-liter) big-block HO V8 engine (P/N 24502618) and 502 engine (P/N 24502620). The heads are 118cc open chamber with 2.18” intake valves and 1.88” exhaust valves with rectangular intake ports. They have 3/8” rocker bolt holes. (Bare Single) [New P/N 12562926]		 --
24502585 BBC DRCE2 Head For DRCE2 Block Part Number 24502572.
      This GM Performance / DRCE2 Cylinder head was designed specifically for the DRCE2 block P/N 24502572. It is intended for professional competition applications. It is designed to comply with NHRA Pro-Stock rules for 500 cu. in. engines with 4.900” cylinder bore spacing. P/N 24502585 is a Raw casting.
     The DRCE2 heat treated head casting is sold as P/N 24502585 or as a semi-finished “cube” with bolt holes as P/N 12480010 (Now P/N 25524405). Special DRCE2 cylinder head features include: High capacity water jacket that is self purging, symmetrical port layout with ample wall material for custom porting designs, thick deck (.850”) surface without cast-in combustion chambers to facilitate “angle milling” without weakening the deck. Reduced weight casting to minimize CNC machine time.
     The DRCE2 cylinder head casting is produced from A356-T6 aluminum with provisions for intake valve angles of 10-14 degrees and canted 5 degrees. The exhaust valve angles of 9-5 degrees with a 2.5 degree cant. The casting is “robust” to provide adequate cylinder head clamping. A typical CNC prepared cylinder head without valves and valve train has a weight of 40 lbs. This DRCE two-head requires aluminum die cast valve cover P/N 12370852.		 --