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: 9/22/2006
Author: MadMike Maciolek
Email: [email protected]

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Small Block Chevy Engine Identification Menu

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Small Block Chevy Crankshaft Casting Numbers

Small Block Chevy Piston Part Numbers

Small Block Chevy Intake Manifold Casting Numbers

Small Block Chevy Exhaust Manifold Casting Numbers

Small Block Chevy Flywheel Part Numbers

Small Block Chevy Flexplate Part Numbers