Small Block Chevy Engine casting numbers and Identification Menu

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Small Block Chevy Engine Identification Menu

General Information & Notes
Body Styles:
A = Chevelle/El Camino , B = Caprice (Full Size), G = Monte Carlo, F = Camaro, H = Vega/Monza
C/K = TRUCK, X = Nova/Chevy II, Y = Corvette
Click here for more information on body types/styles.

Small Block Chevy Crankshafts

All crankshafts have a casting number located on one of the rough finished throws or counterweights towards the front of the crank.

Two types of crankshafts are offered, cast nodular iron and forged steel. Since forged cranks are more expensive to produce, they are generally used only in high performance or severe duty (truck) applications.

Forged crankshafts are easily identified vs cast because a forged crank will have a wide parting line running down the length of the crank, while the cast crank has a thin parting line. Some forged cranks are tufftrided, which is a chemical heat treating process that hardens the bearing journal surfaces. When a crank is tufftrided it will have a dull grey color to it. Many cranks used in severe applications are cross-drilled, which helps ensure constant oiling to the main bearings. All tufftrided cranks are cross-drilled. Not all cross-drilled cranks are tufftrided.

Rear Main Seal
Beginning in 1986 all production small block chevy engines used a 1 piece rear main seal. This means the bolt pattern on the end of the crankshaft was reduced to 3.00".

Journal Size
Journal sizes were increased in 1968.

Rod Main Displacments

Small Journal 2.00" 2.30" 265, 283, 302, 327

Large Journal 2.10" 2.450" 262, 267, 302, 305, 307, 327, 350

400 Crank 2.10" 2.650" 400

Small Block Chevy Crank Stroke

262 ci 3.100" 305 ci 3.484"

265 ci 3.000" 307 ci 3.250"

267 ci 3.484" 327 ci 3.250"

283 ci 3.000" 350 ci 3.484"

302 ci 3.000" 400 ci 3.750"

Small Block Chevy Crankshaft Casting Numbers

Years	Casting	CID	Material	Journal	Rmain Seal	Applications
1968-73	1130	307,327	cast	large	two	all
1968-76	1181	350	cast	large	two	all
	2680	327	steel	small	two
	2690	350	steel		two
1968-69	3279	302	forged	large	two	Z-28
1962-67	4577	327	forged	small	two	-
1968-73	4672	307,327	cast	large	two	-
1975-85	310514	350	-	large	two	-
	330550	350	steel		two
1975-76	354431	262	cast	large	two	Monza,Nova
1955-67	3727449	265,283	forged	small	two	-
	3729449	265	steel		two
1962-67	3734627	327	forged	small	two	-
1955-67	3735236	265,283	forged	small	two	-
1957-63	3735263	283	forged	small	two	-
1962-67	3782680	327	forged	small	two	-
	3814671	327	steel	small	two
1955-67	3815822	265,283	forged	small	two	-
1957-65	3835236	283	forged	small	two	-
1956-63	3836266	265,283	forged	small	two	-
1963-67	3849847	283	cast	small	two	-
1964-67	3876764	283	cast	small	two	-
1964-67	3876768	283	cast	small	two	-
	3884577	327	steel	small	two
1967-76	3892690	350	cast	large	two	-
1968-73	3911001	307,327	cast	large	two	-
	3911011	307,327	cast	large	two
	3914672	327	steel	large	two
	3923279	302	steel	large	two
1969-85	3932442	305,350	cast	large	two	in 1979-82 267
1968-73	3941174	307,327	cast	large	two	-
1968-69	3941178	302	forged	large	two	Z-28
1969-85	3941182	350	forged	large	two	Z28, Vette,truck, some nitrided
	3941188	350	steel		two
1964-67	3949847	283	-	small	two
	3951130	327	steel	large	two
1970-80	3951529	400	cast	XL mns	two	3.76" stroke, ext. bal.
1986-on	14088526	305,350	cast	large	one
1986-on	14088532	350	forged	-	one	truck
1986-on	14088535	305,350	cast	large	one	all
86-88	14088552	350	forged		one

Small Block Chevy Piston Part Numbers

GM P/N	ENGINE	CR/Chamber CC	Dome Type	Pin Type	Material	Usage
12514101	350	8.5:1/76cc	Dish	P	Cast	350/190HP
	-	9.1:1/64cc	-	-	-	350/285HP
	-	-	-	-	-	Crate motor
12361371	350	9.1:1/64cc	Dish	P	Cast	350/300HP Crate motor
10104455	350	9.8:1/58cc	Flat top	P	Hyper	ZZZ 1St design Crate motor
10181389	350	9.8:1/58cc	Flat top	P	Hyper	ZZZ 2nd design Crate motor
12520264	350	9.1:1/64cc	Flat top	P	Cast	350/300HP
3946876	302	11.0:1/64cc	Dome	F	Forged	'68 to '69 Z-28
3942543	350	11.0:1/64cc	Dome	P	Forged	'69 L46
474192	350	9.0:1/76cc	Dish	P	Cast	350 L82
3989051	350	11.0:1/64cc	Dome	P	Forged	'70 LT1
14011020	350	12.5:1/64cc	Dome	F	Forged	Heavy-Duty/NOTE 1
14011021	350	12.5:1/64cc	Dome	F	Forged	Heavy-Duty/NOTE 2
14011026	350	12.5:1/64cc	Dome	F	Forged	Heavy-Duty/NOTE 3
14011027	350	12.5:1/64cc	Dome	F	Forged	Heavy-Duty/NOTE 4

P= Pressed-on pin; F= Floating pin., Hyper = Hypereutectic
Part numbers are for standard (Std.) bore sizes.
NOTE 1: use with 5.7" rod in cylinders 2, 3, 6, 7.
NOTE 2: use with 5.7" rod in cylinders 1, 4, 5, 8.
NOTE 3: use with 6.0" rod in cylinders 2, 3, 6, 7.
NOTE 4: use with 6.0" rod in cylinders 1, 4, 5, 8.

Small Block Chevy Intake Manifold Casting Numbers

Years	Casting	CID	bbls	Material	Carb	Application
1974-76	340261	350	4	iron	Q-jet	A B F X/160,185,195,245,250HP
1973-81	340266	305,350	2	iron	-	A B F G
1982-85	340281	305,350	4	iron	Q-jet	B F
1976-82	346249	305,350	4	iron	Q-jet	all/155,165,205HP
1976-82	346250	305,350	4	iron	Q-jet	all
1973-77	346260	305,350	2	iron	-	A B F
1978-80	373598	305	2	al	-	G
1976-82	458520	305,350	4	al	Q-jet	all
1980-82	1403372	305,350	TTBI	al	cross-fire	F Y
1955	3704790	265	2	iron	-	B
1955	3711348	265	4	iron	-	B Y
1956	3728725	265	8	al	WCFB	Y/225hp, 1st design
1986-57	3731394	283	8	al	WCFB	Y/225hp, 2nd design
1957	3731398	283	4	iron	WCFB, 4jet	B Y
1957	3732880	265,283	2	iron	-	B
1956	3735444	265	2	iron	-	B
1956	3735448	265	4	iron	4BBL	Y /210hp
1956	3737109	265	4	iron	-	B
1957	3739653	283	8	al	-	Y /245,270HP
1957	3741193	283	FI	al	-	B
1957	3746826	265,283	2	iron	-	B
1958-61	3746829	283	4	iron	WCFB, Qjet	B Y/230hp
1962-63	3783244	327	4	iron	WCFB, Qjet	B Y/250hp
1963	3794129	327	4	al	AFB	Y 340hp
1962	3795397	327	4	iron	AFB	Y 340hp
1972	3797771	350	4	iron	-	A B F
1962-64	3799349	327	4	iron	AFB	B Y/300hp
1963-65	3826810	327	FI	-	-	Y
1956-57	3837109	265,283	4	iron	WCFB, Qjet	B Y/210hp
1964-65	3840905	283	2	iron	-	A B X C K
1964-65	3844457	327	4	iron	WCFB, Qjet	A B X Y/250hp, Srvc repl.
1963-65	3844459	327	4	iron	AFB	A B X Y/300hp, srvc repl.
1964-65	3844461	327	4	al	Holley	Y/350,360hp
1962-65	3866922	283,327	4	iron	Qjet	A B X/220hp/250hp, marine use
1966-67	3872783	327	4	iron	Holley	A B X/275hp, w/o AIR, srvc. repl.
1966	3875954	327	4	iron	Qjet	A B X/275hp, w/AIR
1965	3877652	283,327	2	iron	-	A B C K,trk
1966-67	3877656	327	4	al	Holley	350hp Hirise
1966	3882858	283	4	iron	Qjet	A B X/220hp
1966-67	3890490	327	4	al	Holley	X Y/350hp hirise
1966-68	3905393	327	4	iron	Q-jet	A B F X/275hp
1967-68	3910601	327	2	-	-	A F X
1969-70	3916313	307,350	2	-	-	all
1967-68	3917610	302	4	al	Holley	Z-28, F, hirise
1968	3919801	307,327	2	iron	-	A B C X
1967-68	3919803	327,350	4	iron	Qjet	A B F X Y/250,275,325,350HP
1969	3927183	307,327	2	iron	-	A B F X
1969	3927184	350	4	iron	Qjet	A B F X Y/255,300,350HP, srv. rep.
1969	3932472	302	4	al	Holley	Z-28, F, Hirise
1967-69	3941126	302	8	al	Holley	Z28 X ram (bottom) released to race teams in '67 w/o casting#
1967-69	3941130	302	8	al	Holley	Z28 X ram (top) released to race teams in '67 w/o casting#, did have Winter Foundry 'snowflake" logo.
1969-70	3958622	307,327	2	iron
1969-70	3958626	350	2	iron
1971-72	3959594	350	4	al	Holley	Y, Z28, LT1, Hirise, 330/255hp
1970	3965577	350	4	iron	Qjet	B F X/300,350hp
1970	3972110	350	4	al	Holley	Y, Z28, LT1 360,370hp, Hirise
1970	3972114	350	4	al		Z-28, F
	3972116	350	4	al	Holley	hirise, service repl for '70 LT1
1971	3972361	350	4	al	Holley	Z-28, F
1969-71	3973465	307,327	2	-	-	A B F X
1971	3973469	350	4	iron	Qjet	B F Y/270hp
1969-70	3987361	350	-	iron	-
1971	3990948	350	-	iron	-
1973	3991004	350	-	iron	-
1971	3991005	307		iron
1973	3997770	350	4
1973	3997771	350	4	iron	Qjet	all/175,190,245,250hp
1973	3997772	307	-	iron	-
1972	6262928	350	-	iron	-
	6262930		-	iron		Y
1972	6262932	350		iron	-
1971-72		350	4	iron	-
1972	6263751	350	4	iron	Qjet	all, 175,200hp
1973	6271060	350	-	iron
1957	7014360	283	FI	al	-
1957	7014520	283	FI	al	-
1957-58	7014800	283	FI	al	-
1958-59	7014900	283	FI	al	-
1958	7014960	283	FI	al	-
1959-61	7017200	283	FI	al
1959-60	7017250	283	FI	al
1959-60	7017300	283	FI	al
1960-61	7017310	283	FI	al
1960	7017320	283	FI	al
1962	7017355	327	FI	al
1962	7017360	327	FI	al	-
1962-63	7017375	327	FI	al	-
1964-65	7017380	327	FI	al	-
1979-80	14007374	305	2	al	-
1981	14014432	350	4	al	-
1978-85	14057053	305,350	4	al	Qjet	Pass, Camaro, Truck

Small Block Chevy Exhaust Manifold Casting Numbers

FY	LY	Casting	CID	Applications
1973	76	336709	350	F
1973	75	336710	307,350,400	A B F G
1973	80	346222	307,350,400	A B F G
1975	77	346247	350	A B F G
1975	77	346248	350	A B F G
1976	80	364753	305,350,400	all
1970	82	372243	350	Y
1978	82	462697	267,305	G
1978	82	462698	267,305	G
1955	-	3704791	265	B Y
1955	-	3704792	265	B Y
1956	-	3725563	265	B Y
1956	-	3731557	265	B Y
1956	-	3731558	265	B Y
1957	-	3733975	283	B Y
1957	-	3733976	283	B Y
1965	-	3746563	327	Y
1962	68	3747038	283,327	B Y
1958	67	3747042	283	B Y
1964	-	3747938	327
1964	-	3747942	327
1958	63	3749965	283,327	B Y
1958	65	3750556	283,327	B Y
1964	67	3790729	283,327	Chevy II
1965	-	3790730	283,327	Chevy II
1965	-	3791162	283,327	Chevy II
1966	67	3791182	283,327	B
1962	63	3797901	327	Vette
1962	65	3797902	327	Vette
1963	-	3797942	327	Vette
1967	68	3834947	283,327	B
1955	-	3836968	265	B
1955		3837069	265	Y
1964	-	3840715	283,327	A
1964	68	3840912	all	A F X
1964	71	3846559	327,350	Vette
1964	65	3846563	327	Vette
1964	67	3849288	283,327	Chevy II
1964	67	3849290	283,327	Chevy II
1964	68	3855163	283,327	B C K
1966	67	3872723	283,327	Chevy II
1966	-	3872729	283,327	A
1967	68	3872730	all	A F
1966	67	3872738	283,327	Chevy II
1966	68	3872741	283,327	B
1967	71	3872765	327,350	Vette
1966	68	3872778	283,307,327	B C K Y
1964	67	3890424	283,327	Chevy II
1967	-	3892679	all	A F X
1967	68	3892683	all	A F
1966	68	3893604	283,327	B
1967	-	3893608	all	A F
1967	68	3896956	283,307,327	C K
1967	68	3905364	307,350,400	C K
1969	70	3932376	307,350	A F
1970	72	3932461	350	Vette
1969	70	3932465	327,350	B
1969	70	3932469	350,400	B
1969	70	3932473	307,350	B
1969	-	3932481	350	Y
1967	-	3940972	350	F
1969	71	3942527	302,307,350	A F X
1969	70	3942529	307,350	A F X
1969	-	3946826	302,307,350	A F X
1969	-	3946826	302
1972	73	3959562	307,350	A F
1971	72	3973432	307,350	A B F X
1972	74	3986330	307,350	F
1970	72	3989036	350,400	B Y
1969	73	3989041	302,307,350	A F X
1970	73	3989043	307,350	A B F X

Small Block Chevy Flywheel Part Numbers

Part #	DIA.	Teeth	Comments
3991469	14"	168	two-piece seal, internally balanced
3986394	14"	168	400 External balance, two-piece seal
10105832	14"	168	86-later, one-piece rear seal, ext. balance
14085720	12.75"	153	Lightweight (15 lbs.), nodular iron, two-piece seal, int bal
14088646	12.75"	153	86-up, Lightweight (15 lbs.), nodular iron, one-piece rear seal, ext bal
14088648	14"	168	86-up, one-piece rear seal, ext. balance
14088650	12.75"	153	86-up, one-piece rear seal, ext balance
10174482			89-up with six-speed m/t, requires starter (10455709)
Common clutch sizes are: 10.4", 11.0", and 11.85". Some flywheels are drilled for two different clutch patterns.

Small Block Chevy Flexplate Part Numbers

Part #	DIA.	Teeth	Comments
471529	12.75"	153	Two-piece seal blocks, int balance
471578	14"	168	400 ext. bal, two-piece rear seal
471598	14"	168	Two-piece seal blocks, internal balance
10128412	12.75"	153	86-up, one-piece rear seal ext. balance
10128413	14"	168	86-up, one-piece seal, extra thick, HD, ext bal
10128414	14"	168	86-96, one-piece rear seal, ext. balance
14088761	14"	168	89-up 350 HO, one-piece rear seal, ext. bal.
14088765	12.75"	153	86-up, one-piece rear seal, ext. bal.
14088767	14"	168	89-up 350 HO, one-piece rear seal, HD, ext. bal

Last updated: 10/20/2011
Author: MadMike Maciolek

Return to Main Decoding Page

	Rod	Main	Displacments
Small Journal	2.00"	2.30"	265, 283, 302, 327
Large Journal	2.10"	2.450"	262, 267, 302, 305, 307, 327, 350
400 Crank	2.10"	2.650"	400

Small Block Chevy Crank Stroke
262 ci	3.100"	305 ci	3.484"

265 ci	3.000"	307 ci	3.250"
267 ci	3.484"	327 ci	3.250"
283 ci	3.000"	350 ci	3.484"
302 ci	3.000"	400 ci	3.750"