SBC cylinder head identification

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:The casting number may be out in the open where it can be easily seen, like the Pontiac V8, or somewhat harder to see but still visible without taking anything off the head, or the number can be under the valve cover or under the head where it's difficult to see without some amount of disassembly.
 
:The casting number may be out in the open where it can be easily seen, like the Pontiac V8, or somewhat harder to see but still visible without taking anything off the head, or the number can be under the valve cover or under the head where it's difficult to see without some amount of disassembly.
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;Casting date  
 
;Casting date  
 
:Like casting numbers, the date code is usually cast into the head, and may or may not be visible without removing the valve cover.
 
:Like casting numbers, the date code is usually cast into the head, and may or may not be visible without removing the valve cover.
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;Secondary identifier(s)
 
;Secondary identifier(s)
 
:These are often stamped in instead of cast, like in the case of some 1970's Pontiac heads.
 
:These are often stamped in instead of cast, like in the case of some 1970's Pontiac heads.
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;Casting identifiers
 
;Casting identifiers
 
:This is different shapes that may be (in the case of the SBC) on the end of the heads or elsewhere.
 
:This is different shapes that may be (in the case of the SBC) on the end of the heads or elsewhere.
 
    
 
    
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==Chevrolet==
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=Chevrolet=
  
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===Casting numbers===
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==Casting numbers==
 
Located under the valve covers, the casting number is the best way to ID a SBC head. The number along with the date code can be used to pinpoint the heads original application fairly closely. Valve sizes (1.94" intake x 1.5" exhaust or 2.02" intake x 1.60" exhaust) and whether or not screw-in studs and guide plates are in place can further ID them. Be aware that screw-in studs/guide plates were not used on all, or even most, large valve SBC performance heads from the factory, and if present, they could very well have been added previously.
 
Located under the valve covers, the casting number is the best way to ID a SBC head. The number along with the date code can be used to pinpoint the heads original application fairly closely. Valve sizes (1.94" intake x 1.5" exhaust or 2.02" intake x 1.60" exhaust) and whether or not screw-in studs and guide plates are in place can further ID them. Be aware that screw-in studs/guide plates were not used on all, or even most, large valve SBC performance heads from the factory, and if present, they could very well have been added previously.
  
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===Casting identifiers===
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Click [[Cylinder head identification#Resources|'''HERE''']] for casting number ID sites.
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==Casting identifiers==
 
Through the years, small block Chevy heads have been ID'd by the head's end casting shapes. They don't usually tell the exact details like valve sizes but are useful for telling (at least potentially) a performance head from a non performance head. A casting identifier can differentiate between a large or small combustion chamber volume, also intake port volume, spark plug type (gasketed or tapered seat), whether they were used with a certain type of front accessory arrangement (short or long water pump for instance).
 
Through the years, small block Chevy heads have been ID'd by the head's end casting shapes. They don't usually tell the exact details like valve sizes but are useful for telling (at least potentially) a performance head from a non performance head. A casting identifier can differentiate between a large or small combustion chamber volume, also intake port volume, spark plug type (gasketed or tapered seat), whether they were used with a certain type of front accessory arrangement (short or long water pump for instance).
  
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===="Fuelie" heads====
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=="Fuelie" heads==
 
The most recognized end casting identifier of the SBC heads is the "fuelie", "double hump", or "camel hump". It got the name fuelie from the fact that it was used on the fuel injected Corvette engines. Double hump and camel hump is from the physical shape of the casting. The fuelie heads was used from the 1960's to the 1970's on the high performance optional engines up to and including the 375 HP fuel injected L-84 327 cid engine, and the 365 HP L-79 4-barrel engine of 1964, and the bad-to-the-bone LT-1 engine, to name just three.
 
The most recognized end casting identifier of the SBC heads is the "fuelie", "double hump", or "camel hump". It got the name fuelie from the fact that it was used on the fuel injected Corvette engines. Double hump and camel hump is from the physical shape of the casting. The fuelie heads was used from the 1960's to the 1970's on the high performance optional engines up to and including the 375 HP fuel injected L-84 327 cid engine, and the 365 HP L-79 4-barrel engine of 1964, and the bad-to-the-bone LT-1 engine, to name just three.
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'''462''' is the most-used SBC head casting number out there- at least six different SBC cylinder head casting numbers end in 462, according to 'the books':
 
'''462''' is the most-used SBC head casting number out there- at least six different SBC cylinder head casting numbers end in 462, according to 'the books':
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• 3891462
 
• 3891462
 
<br style="clear:both"/>  
 
<br style="clear:both"/>  
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===Other fuelie casting identifiers===
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[[File:Fuelie end ids1.jpg]]
  
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====Diagrams of some common small block Chevy head ID castings====
 
  
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==Vortec L30 5.0L heads==
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==Vortec L31 5.7L heads==
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The L31 5.7L Vortec casting numbers are '''12559062''' and '''10239906'''.
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[[File:062_VORTEC_END_ID_001.jpg|left|frame|Casting number 12558062 Vortec head has 3 small humps, aka "sawtooth" on the end of the head.]][[File:906 VORTEC END ID.jpg|right|frame|Casting number 10239906 Vortec head has one large single hump on the end of the head.]]
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<br style="clear:both"/>
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===Vortec exhaust seats===
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Early on, there was much made of the supposed difference in flow between the Vortec heads that came with the hardened exhaust seat inserts as opposed to the heads that had induction hardened seats. This was largely due to an oft-repeated, although incorrect statement made by a car magazine that said in essence the 904 head was to be avoided because of the exhaust seat insert being vastly inferior to the heads with induction hardened exhaust seats.
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The truth has been shown to be that there is virtually no difference in flow between the two, providing the seat is blended into the port. This is a common procedure that's often done in performance builds- regardless of whether the seats are inserts or induction hardened or unhardened. The manufacturing process leaves a lip where the seat and port pocket meet in many instances, and it's this lip that is carefully removed/blended when a head is prepped for performance use, again- regardless of whether there is an insert or not.
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So both the c/n 906 and c/n 062 heads have virtually the exact same performance potential. In fact there are instances like for marine use where the hardened exhaust seat insert is actually preferred over the induction hardened seat.
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{|
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|[[File:Induction hardened seat vortec.jpg|thumb|center|400px|Induction hardened Vortec exhaust seat.]]
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|[[File:Hard insert seat vortec 906.jpg|thumb|center|400px|Hardened insert Vortec exhaust seat.]]
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|}
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==Various SBC chamber comparisons==
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<Gallery>
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File:Early chamber left vortec right.jpg|Early 64 cc chamber, left vs. L31 5.7L Vortec 64 cc chamber, right.
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File:87 96vortec3.jpg|1987-'95 center bolt chamber, left vs. Vortec chamber, right.
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File:Sbc swirl port chamber.jpg|TBI swirl port 64 cc chamber.
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</gallery>
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<br style="clear:both"/>
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==Diagrams of some common small block Chevy head ID castings==
 
[[File:CastingMarkssbcheads.jpg]]
 
[[File:CastingMarkssbcheads.jpg]]
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<Gallery>
 
<Gallery>
 
File:041 sbc cast id.jpg|SBC casting number 3947041, "G" below.  
 
File:041 sbc cast id.jpg|SBC casting number 3947041, "G" below.  
 
File:292 angle plug.gif|SBC angle plug "Turbo" casting number 340292.
 
File:292 angle plug.gif|SBC angle plug "Turbo" casting number 340292.
 
</Gallery>
 
</Gallery>
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<gallery>File:Head388.jpg|C/n 3986388; ’68-’79 1.72" x 1.5" valves.
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File:Head450.jpg|C/n 376450; 350 1987-’94 76 cc 1.94" x 1.5" valves.
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File:Head487.jpg|C/n 3973487; ’68-’79 76 cc 1.94" or 2.02" valves.
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File:Head882.jpg|C/n 333882; ’70-’80 76 cc 1.94" x 1.5" valves.
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</Gallery>
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<br style="clear:both"/>
 
[[File:Sbc head casting id.jpg]]
 
[[File:Sbc head casting id.jpg]]
 
   
 
   
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*'''P-'''  Double (Captain’s) bars c/n 193. Used on TBI equipped engines. Mid-1980- up style centerbolt valve cover. Has restrictive vane cast in intake port to induce swirl/turbulence. Not usually recommended for high RPM performance applications unless serious port work is done. Hardened exhaust seats.
 
*'''P-'''  Double (Captain’s) bars c/n 193. Used on TBI equipped engines. Mid-1980- up style centerbolt valve cover. Has restrictive vane cast in intake port to induce swirl/turbulence. Not usually recommended for high RPM performance applications unless serious port work is done. Hardened exhaust seats.
  
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====Vortec L30 5.0L heads====
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==SBC heads to avoid==
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*The c/n 462624 is said to be very prone to cracking. Even though they can be found fitted with 2.02" x 1.60" valves and screw in studs/guide plates from the factory, they still are not a good choice for serious performance use.
  
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====Vortec L31 5.7L heads====
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*1971-up heads with casting numbers 882, 993, 487, 336 (and others) can have 3/8" exhaust stems as well as 1.72" intake valves. Heavy 20-30 Series truck uses these, mainly. Both small 1.72" intake and 3/8" stem exhaust valves may be found on c/n's 261, 624. Also 1987-'95 center bolt valve cover-type head c/n 14102191 can also have the 3/8" exhaust valve stem.
  
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The L31 5.7L Vortec casting numbers are '''12559062''' and '''10239906'''.
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*Usually swirl port TBI SBC heads are not used in high performance applications because they run out of breath earlier than the RPM most performance camshafts need to make peak power. Some casting numbers for them are 187, 191, 193. Similar heads, but without the swirl-inducing vane
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[[File:062_VORTEC_END_ID_001.jpg|left|frame|Casting number 12558062 head has 3 small humps, aka "sawtooth" on the end of the head.]][[File:906 VORTEC END ID.jpg|right|frame|Casting number 10239906 head has one large single hump on the end of the head.]]
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<br style="clear:both"/>
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<Gallery>
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File:Early chamber left vortec right.jpg|Early 64 cc chamber, left; L31 5.7L Vortec 64 cc chamber, right
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File:Sbc swirl port chamber.jpg|SBC TBI swirl port 64 cc chamber.
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File:Head388.jpg|C/n 3986388; ’68-’79 1.72" x 1.5" valves.
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File:Head450.jpg|C/n 376450; 350 1987-’94 76 cc 1.94" x 1.5" valves.
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File:Head487.jpg|C/n 3973487; ’68-’79 76 cc 1.94" or 2.02" valves.
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File:Head882.jpg|C/n 333882; ’70-’80 76 cc 1.94" x 1.5" valves.
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</Gallery>
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<br style="clear:both"/>
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====SBC heads to avoid====
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The c/n 462624 is said to be very prone to cracking. Even though they can be found fitted with 2.02" x 1.60" valves and screw in studs/guide plates from the factory, they still are not a good choice for serious performance use.
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1971-up heads with casting numbers 882, 993, 487, 336 can have 3/8" exhaust stems as well as 1.72" intake valves. Heavy 20-30 Series truck use, mainly. Both small 1.72" intake and 3/8" stem exhaust valves may be found on c/n's 261, 624. Also 1987-'95 center bolt v-cover-type head # 14102191 can have the 3/8" exhaust valve.
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Usually swirl port TBI SBC heads are not used in high performance applications because they run out of breath earlier than the RPM most performance camshafts need to make peak power. Some casting numbers for them are 187, 191, 193. Similar heads, but without the swirl-inducing vane
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are c/n's 14011083 and 14096217.
 
are c/n's 14011083 and 14096217.
  
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==AMC==
 
  
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=AMC=
  
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==Ford==
 
  
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=Ford=
  
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==Mopar==
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=Mopar=
  
 
==Resources==
 
==Resources==
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*[http://outintheshop.com/faq/casting/castings2.html SBC head casting number go-to site]
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;SBC casting numbers
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*[http://outintheshop.com/faq/casting/castings2.html SBC head casting number "go-to" site]
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*[http://web.archive.org/web/20080518030656/http://www.mortec.com/ MorTec archived]
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[[Cylinder head identification# Casting numbers|'''Return to top'''.]]
  
 
[[Category:Identification and decoding]]
 
[[Category:Identification and decoding]]
 
[[Category:Engine]]
 
[[Category:Engine]]
 
[[Category:undeveloped articles]]
 
[[Category:undeveloped articles]]
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Revision as of 08:41, 25 March 2012

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