Big Block Chevy Engine Parts Identification

Big Block Chevy Engine Parts Identification

BBC Engine Block Casting Numbers

Casting #	Year	CID	HP/RPO/Comments/Applications
340220	1972-76	427	tall truck
345014	1974-86	454	truck
346236	1974-76	454	215, 2 bolt
359070	1974-90	454	truck
361959	1973-85	454	car & truck
364776	1968-84	427	tall truck
364779	1968-88	366	tall truck
473478	1968-84	427	tall truck
3782870	1968-76	427	tall truck
3855061	1965-67	396
3855961	1966-67	396	325, 360, 2 bolt
3855962	1965-66	396	360, 375, 425, 4 bolt
3855977	1965-67	366	tall truck
3866961	1966-69	396	Chevy, Chevy truck
3869942	1966-67	427	390, 425, 2&4 bolt
3873858	1966	396	375, 4 bolt
3902406	1967	396	325, 350, 375, 2&4 bolt
3902466	1965-67	396
3904351	1967	427	385, 390, 400, 425, 430, 435, 2&4 bolt
3904354	1966-67	366	tall truck
3916319	1968-85	366	tall truck
3916321	1968	427	385, 390, 400, 425, 430, 435, 2&4 bolt
3916323	1968	396	325, 350, 375, 2&4 bolt
3918319	1966-70	366	Chevy truck, GMC, tall truck
3925521	1968-85	366	tall truck
3928319	1969-73	366	GMC, tall truck
3935439	1968-69	427	335, 390, 400, 425, 430, 435, 2&4 bolt
3935440	1968-69	396	265, 325, 350, 375, 2&4 bolt
3937724	1968-85	366	tall truck
3937726	1968-84	427	tall truck
3955270	1969	427	335, 390, 400, 425, 430, 435, 2&4 bolt
3946052	1969	427	430 ZL-1, 4 bolt, aluminum
3955272	1969	396/402	265, 325, 350, 375, 2&4 bolt
3955274	1968-85	366	tall truck
3955276	1968-84	427	tall truck
3963512	1969-71	427	335, 390, 400, 425 COPO, 430, 435,
		454	345, 360, 365, 390, 425, 450 2&4 bolt
3963513	1973-76	454	215
3965440	1968-69	396
3965449	1968-72	396
3965540	1968	396
3969854	1969-72	396/402	240, 265, 300, 325, 330, 350, 375,
		454	360, 2&4 bolt
3969858	1968-84	427	tall truck
3999289	1972-78	454	215, 235, 240, 270, 2 bolt, car & truck
3999290	1972	402	240, 2 bolt
3999293	1968-85	366	tall truck
3999294	1968-84	427	tall truck
6272176	1968-76	366	Chevy, GMC, tall truck
6272177	1972	402	210
6272181	1973-76	427	tall truck
1401544	1975-87	454	truck

Big Block Chevy Cylinder Heads
Open vs. Closed Chamber - A good way to describe big-block heads is to categorize them as open or closed chamber. Closed-chamber cylinder heads have small combustion chamber volumes for high compression ratios, with even mildly domed pistons. Open-chamber designs are larger and provide lower compression ratios, so require a much larger piston dome to achieve the same compression as a closed-chamber head.

Use of either style head requires that the correct pistons are used, otherwise...

BBC Cylinder Head Casting Numbers
RECTANGULAR PORT - Valve size 2.19 intake, 1.88 exhaust

Casting	Years	CID	Chamber	CC	HP/RPO/Comments
3904392	1967	427	Closed	106.8	430, 435 L-88/L-89, 1.72 ex
3919842	1968-69	396			375 L-89
		427	Closed	106.8	430, 435 L-88/L-89, 1.84 ex
3946074	1969-71	396,402			375 L-89, 427 430 L-88/ZL-1
		454	Open	118.0	425, 465 LS-6/LS-7, round ex
10051128	1990-94	454	Semi Open		72cc, IP 400cc, bowtie, sym port
14011077	1989-94	454	Open		118.0cc, IP 295cc, replacement, C port
14044861	1989-94	454	Open		425, 105.0cc, IP 380cc, bowtie, W port
3856208	1965	396	Closed	108.9	375, 425 Z-16/L-37, 1.72 ex
3873858	1966-67	396			375 L-78
		427	Closed	108.9	425 L-72, 1.72 ex
3904391	1965-67	396			375 L-78
		427	Closed	106.8	425, 435 L-71/L-72, 1.72 ex
3919840	1967-69	396			375 L-78, 1.72.ex
		427	Closed	109.0	425, 435 L-71/L-72, 425 COPO
3964291	1969-70	396/402			375 L-78, Intake Port 325cc
		427			425, 435 L-71/L-72
		454	Closed		450 LS-6, 108.0cc
3964292	1970	454	Closed		450 LS-6, 109.0cc
3994025	1971	454	Open		425 LS-6, 118.0cc
3994026	1971	454	Closed		425 LS-6, 118.0cc
6258723	1971	454	Open		425
6272990	1971-94	454	Open		425, 118.0cc, IP 325cc
14096188	1987-94	454	Open		425, 118.0cc, IP 325cc, replacement
14097088	1989-94	502	Open		GEN V, 118.0cc, IP 325cc, replacement

OVAL PORT - Valve size 2.06 intake, 1.72 exhaust

Casting	Years	CID	Chamber	CC	HP/RPO/Comments
330864	1970-81	366/427/454	Open
330865	1970-84	366/427/454	Open
336765	1973-84	427/454	Open
336781	1973-85	454	Open		113.0cc
343771	1968-85	366/427/454	Open
343772	1976-84	366/427/454	Open
343783	1975-78	454	Open		car & truck
346236	1975-87	454	Open		113.0cc
346238	1975-87	454	Open		113.0cc
353049	1970-73	402/454	Open		113.0cc
473328	1968-85	366	Open
3856206	1965-66	396	Closed		325 97.2cc
3856213	1966-70	366	Closed		truck
3872702	1966	396			325, 360 L-34/L-35
		427	Closed		390, L-36 98.4cc
3876875	1966-70	427	Closed		truck
3904390	1966-67	396			325, 350 L-34/L-35
		427	Closed		390, 400, L-36/L-68 98.4cc
3904393	1966-68	366	Closed		truck
3909802	1966-67	396			325, 350 L-34/L-35
		427	Closed		385, 390, 400, L-36/L-68 100.9cc
3917215	1967-69	396			325, 350 L-34/L-35
		427	Closed		335, 385, 390, 400 100.9cc
3917219	1966-70	366/427	Closed		truck
3931063	1969-70	396			325, 350 L-34/L-35
		427	Closed		335, 385, 390, 400 100.9cc
3933148	1969	366/396	Open		2V/427 265 122.1cc car & truck
3933149	1969-70	427	Open		122.1 cc truck
3964280	1966-70	427			335, 385, 390, 400
		454	Closed		345, 360, 390 LS-5
3964290	1969-70	396/402			325, 330, 350
		427			335, 385,390, 400
		454	Closed		345, 360, 390 LS-5 100.9cc
3965198	1969	396			truck
3975950	1968-70	366/427	Closed		truck
3986133	1970-85	366/427	Closed		truck
3986136	1970-84	366/427	Closed		truck
3993820	1971	402			300, 330 LS-3
		454	Open		365 LS-5 113.0cc
3999241	1972	402			240, 300, 330 LS-3
		454	Open		365 LS-5 113.0cc
6272292	1971	402			240, LS-3
		454	Open		270, LS-5
10101136	1991-94	454	Open		truck
10121033	1978-88	454	Open		truck
12352783	1979-93	454	Open		truck
14025175	1983-93	454	Open		truck
14081044	1986-90	454	Open		truck
14092359	1986-89	427	Open		truck
14092360	1985-89	454	Open		truck
14101398	1986-90	454	Open		truck

BBC Camshaft Part Numbers

Part #	Year	Type	Lift	Dur @ .050 lift	Comments/Specs/RPO's/Apps
340282		Solid	.560I/.560E	.262I/.262E	121 deg overlap, competition-short track apps
353040	1973-74	Hyd	.440I/.440E	.210I/.210E	production Corvette
3863143	1965-71	Solid	.520I/.520E	.242I/.242E	See Note 1
3883986	1965-72	Hyd	.460I/.488E	.213I/.217E	See Note 2
3904362	1965-71	Solid	.520I/.520E	.242I/.242E	See Note 3
3925533	1965-69	Solid	.540I/.560E	.262I/.269E	133 deg overlap, 427 L-88, Reverse rotation
3925535	1965-69	Solid	.540I/.560E	.262I/.269E	133 deg overlap, 427 L-88, standard rotation
3959180	1969-70	Solid	.560I/.600E	.262I/.273E	135 deg overLap, 427 ZL-1, 454 LS-7
3994094		Solid	.600I/.600E	.286I/.286E	See Note 4
6272989		Hyd	.500I/.500E	.222I/.221E	121 deg overlap, marine grind or HP street
14096209		Hyd	.500I/.500E	.222I/.221E	121 deg overlap, marine grind or HP street (6272989)

Note 1: 80 deg overlap, 396 375hp L-78/L-89, 427 425/435hp L-71/L-72, 454 450hp LS-6, HP street
Note 2: 396 325/350hp L-34/L-35, 427 385/390/400hp L-36/L-68, 454 345/360/390hp LS-4/LS-5, good torque/HP
Note 3: 80 deg overlap, 396 375hp L-78/ L-89, 427 425/435hp L-71/L-72, 454 450hp LS-6, HP street
Note 4: 148 deg overlap, maximum power with F.I. or tunnel ram, Can Am

BBC Crankshaft Part Numbers

Casting #	Year	CID	Comments/Specs/RPO's/Apps
330570		427	truck,1053,forging number 6223
336782	1970-74	454	with automatic transmission
3879621	1967	427	L-88, See Note 1
3882841	1965-71	396	See Note 2
3882842	1965-69	427	forged, cross drilled, balanced for 11:1 CR
3882849	1966-69	427
3887114	1965	396	tufftrided, 5140
3963521		454	4 in stroke, 5140, raw forged
3963523	1970-71	454	LS-6, See Note 3
3963524	1970-71	454	LS-7, See Note 4
3965746	1965-69	430	raw forged, semi finished, 3.4-3.8 stroke
3965753	1970-72	495	raw forged, semi finished, 3.9-4.25 stroke, 5140
3967811	1968-69	427	L-88/ZL-1, See Note 5
3975945	1970	454	with manual transmission
3993804		427	raw forged, 3.75 stroke, 5140
3993878	1971-72	454	LS-6
10051169		454	raw forged, 4340, 3.75-4.25

Note 1: L-88, with 3/8 in bolt rods, balanced for 12.5:1 CR, tufftrided, cross drilled
Note 2: forged, cross drilled, 3.76 stroke, tufftrided, balanced for 11:1 CR
Note 3: 1053, tufftrided, cross drilled, balanced for 9.25:1 or 11.25:1 CR, forging number - 3520 and 7416
Note 4: 4 in stroke, HD, 5140, LS-7, balanced for 12.5:1 CR, tufftrided, cross drilled
Note 5: tufftrided, 5140, with 7/16 in bolt rods, tufftrided, cross drilled, forging number - 7115

BBC Exhaust Manifold Casting Numbers

Cast #	Years	Side	CID	Applications
329225	1973-76	LH	454
353028	1973-76	LH	454
353030	1973-76	LH	454	police
3856297	1965	LH	396	325
3856301	1965	LH	396	425 Corvette
3856302	1965	RH	396	425 Corvette
3856306	1965	RH	396	325
3857297	1965	LH	396	325
3868874	1965-66	RH	396	325, 360, 375 Z-16
3869925	1965	LH	396	375 Z-16
3872770	1966	RH	396
3880827	1966-69	LH	427/454	Corvette
3880828	1966-72	RH	427/454	Corvette
3880869	1970-72	LH	454	Corvette
3883999	1966	LH	396	325, 360, 375
3884504	1966-67	RH	396/427	325, 385, 390
3892307	1966-67	LH	396/427	325, 390
3902401	1967	LH	396
3904399	1966	LH	396
3909879	1967-70	LH	396/427	COPO/454 325, 350, 375, 425, 430
3909880	1967	RH	396	325, 350, 375
3914613	1968-70	LH	396/427	265, 325, 335, 345, 390, 425
3916178	1968-70	RH	396/427	COPO/454 325, 350, 375, 425, 430
3969869	1970-74	LH	454	Corvette
3989310	1971-72	RH	402/454
3989343	1971-72	LH	402/454
3994045	1973-75	LH	454	police

BBC Intake Manifold Casting Numbers
ALUMINUM RECTANGULAR PORT - Holley 4V

Casting	Years	CID	HP/RPO/Config
3866963	1965	396	375, 425 L-37
3885069	1966-68	396	375 L-78
		427	425 L-72
3886093	1967	427	430 L-88
3894374	1967	427	435 3x2 L-71
3894382	1967	427	400 3x2 L-68, oval port
3919849	1968	427	390 L-36, oval port, Qjet
3919850	1968	427	400 3x2 L-68, ovat port
3919852	1968	427	435 3x2 L-71
3919878	1968	396	375 L-78
		427	425 L-72
3933163	1968-69	396	375 L-78/L-89
		427	425 copo
3933198	1968-69	427	430 L-88/ZL-1
3937793	1968	427	390 L-36, oval port, Qjet, Late
3937795	1969	427	400 3x2 L-68, oval port
3937797	1969	427	435 3x2 L-71
3947801	1969	427	390 L-36, oval port, Qjet
3963569	1970-71	396/402	375 L-78/L-89
		454	LS-6, lowrise
3967474	1971	454	425
6269318	1972	454

BBC Intake Manifold Casting Numbers
IRON OVAL PORT - Rochester Q-jet 4V

Casting	Years	CID	HP/RPO/Config
336789	1974	454	235, 270
346242	1975	454	215
353015	1973	454	215, 245
393841	1973-75	454	215
3856289	1965-66	396	325 L-35
3866948	1966-67	396	325, 360 L-34/L-35
		427	390, Holley
3883948	1966-68	396	325 L-35
		427	385, 390 L-36
3931067	1969	396	325 L-35
		427	335, 390 L-36
3952900	1969	396	265 2V
3955287	1970-71	402	300, 330, 350 LS-3
		454	360, 365, 390
6263753	1972	402	240 LS-3
		454	240, 270

Creation Date: 1/30/1998
Last revision: 12/2/1998 - Reformatting head CC info
Author: MadMike Maciolek
Email: iracez28@stc.net
Email: m_maciolek@vmsnet.enet.dec.com

Introduction

When I started this Web site back in 1996 there wasn't much information about big block Chevy engines on the Web, so I decided to create this page. I don't claim to be an expert about engines and am simply sharing some of the information that I've compiled from many different sources. Eventually I'd like to be able to provide some good technical information, especially about cylinder heads, and also make the casting number lists as complete as possible for those of us that are hunting around for old blocks, cranks and heads.

I'd also like to be able to provide more information on is the maximum bore size that can be reliably used on various big blocks. I've heard of people going as much as .125" over stock on some early 396 blocks, although you'd certainly want to check the wall thickness of the block with a sonic thickness tester before taking one out that far. Aftermarket pistons are available for .090" 454s and in some cases as much as .125" over.

Preparing an Engine Block for Machining

The first step in preparing a block is to get it clean. Begin by scraping off any gasket adhesive and the worst of the built-up grease. Even with all of the right tools, tearing down a block can test your patience, and I recommend having the shop that's going to clean the block also remove all of its plugs. If you want to do it yourself, here's how:

All of the freeze plugs need to be removed with a hammer and punch. Pull them out with pliers before you knock them all the way into the water jackets. (Otherwise, since they're non-magnetic, you'll have to keep moving the block around until the plug lands over one of the holes for them, getting a grip on it with the pliers, and pulling it out. This is how we learn humility.) Now out come the oil gallery plugs, which have weird square female heads that even with the proper Snap-On tool still often have to be carefully drilled out.

The lifter galley and the entire inside of the block were then fully deburred to remove all of the "pockets" where casting sand and metal may come loose, something I'd suggest to anyone building an engine. I used a die grinder with emery cloth cartridges, which makes it possible to reach into all of the block's contours.

Once you've got the block completely bare (except for the leaving main caps in the right places) and deburred, you're ready to call the local engine rebuilder and find out when they're changing their solution so you can get it in their tank when it's not full of sludge. The shop I took the block to for it to be hot tanked let me bring it in right after they changed their tank's solution on a Friday afternoon, and we lowered it in and let it spend the whole weekend thinking over how badly it wanted to hang onto the last of its grease. Monday morning I was there early to hoist it out of the tank, and spent a full fifteen minutes running water all over it and through all of the passages, ending up with something that was clean. Then I got an air line and got the entire block completely dry, and it was ready for machining.

Big Block Chevy Bore and Stroke

Engine Size	Stock Bore	+.060"-over	Stock Stroke
366	3.935"	3.995"	3.760"
396	4.094"	4.154"	3.760"
402	4.125"	4.185"	3.760"
427	4.250"	4.310"	3.760"
454	4.250"	4.310"	4.000"
Mark 5 — 502 — Mark 6	4.468"	4.530"	4.000"

454 Engines	3.760"	4.000"	4.250"	4.500"	4.750"	4.875"
Stock bore = 4.250"	427"	454"	482"	511"	539"	553"
Bored .030" = 4.280"	433"	460"	489"	518"	547"	561"
Bored .060" = 4.310"	439"	467"	496"	525"	554"	569"
Bored .090" = 4.340"	445"	473"	503"	533"	562"	577"
Bored .100" = 4.350"	447"	476"	505"	535"	565"	580"
Bored .125" = 4.375"	452"	481"	511"	541"	571"	586"

502 Engines	3.760"	4.000"	4.250"	4.500"	4.750"	4.875"
Stock bore = 4.468"	472"	502"	533"	564"	596"	611"
Bored .032" = 4.500"	478"	509"	541"	573"	604"	620"
Bored .062" = 4.530"	485"	516"	548"	580"	612"	629"
Bored .092" = 4.560"	491"	523"	555"	588"	621"	637"

Brodix, Dart & Merlin Blocks	4.000"	4.125"	4.250"	4.375"	4.500"	4.625"	4.750"	4.875"	5.000"
4.500" bore	509"	525"	541"	557"	572"	588"	604"	620"	636"
4.530" bore	515"	532"	548"	564"	580"	596"	612"	628"	645"
4.560" bore	523"	539"	555"	572"	588"	604"	621"	637"	653"
4.590" bore	530"	546"	563"	579"	596"	612"	629"	645"	662"
4.600" bore	532"	548"	565"	582"	598"	615"	632"	648"	665"
4.625" bore	537"	554"	571"	588"	605"	622"	638"	655"	672"

To calculate the displacement of an eight-cylinder engine: Bore x Bore x Stroke x 6.2832

Cubic inches x 16.387 = cubic centimeters

Cubic centimeters x .061 = cubic inches

The Five Largest Bonneville Salt Flats Engine Classes

AA / Fuel and AA / Gas	501 cubic inches and over	8.21 liters and over
A / Fuel and A / Gas	440 to 500 cubic inches	7.21 liters to 8.19 liters
B / Fuel and B / Gas	373 to 439 cubic inches	6.11 liters to 7.19 liters
C / Fuel and C / Gas	306 to 372 cubic inches	5.01 liters to 6.10 liters
D / Fuel and D / Gas	261 to 305 cubic inches	4.27 liters to 5.00 liters

BBC Engine Block Casting Numbers

Number	Size	Rated Horsepower	Production	Main Caps
340220	427		1968-1976	Four-bolt (tall-deck)
346236	454		1975	Two-bolt
361959	454		1978-1987	Two-bolt or four-bolt
364776	427		1974-1976	Four-bolt (tall-deck)
364776	454		1977-1990	Four-bolt (tall-deck)
364779	366		1968-1990	Four-bolt (tall-deck)
473478	427		1977-1990	Four-bolt (tall-deck)
1014183	366		1991-1992	Four-bolt (tall-deck)
3855961	396	325 and 360	1966	Two-bolt
3855962	396	360, 375, and 425	1965-1066	Two-bolt or four-bolt
3869942	427	390 and 425	1966	Two-bolt or four-bolt
3873858	396	375	1966	Four-bolt
3902406	396	325, 350, and 375	1967	Two-bolt or four-bolt
3904351	427	425	1967	Four-bolt
3916321	427	425 and 435	1968	Four-bolt
3916323	396	325, 350, and 375	1968	Two-bolt or four-bolt
3935439	427	435	1968 and 1969	Four-bolt
3935440	396	350 and 375	1969	Two-bolt or four-bolt
3937724	366		1968-1976	Four-bolt (tall-deck)
3955272	396	325, 350, and 375	1969	Two-bolt or four-bolt
3955272	402	325, 350, and 375	1969	Two-bolt or four-bolt
3955274	366		1968-1976	Four-bolt (tall-deck)
3955276	427		1968-1973	Four-bolt (tall-deck)
3963512	454	360, 375, 425, and 460	1968-1971	Two-bolt or four-bolt
3969852	366		1968-1976	Four-bolt (tall-deck)
3969854	402	360 and 375	1972	Two-bolt
3969854	454	360 and 375	1972	Two-bolt
3969858	427		1968-1973	Four-bolt (tall-deck)
3999289	454		1972-1979	Two-bolt
3999290	402	240	1972	Two-bolt
3999293	366		1968-1976	Four-bolt (tall-deck)
3999294	427		1968-1973	Four-bolt (tall-deck)
10114182	454		1992	Four-bolt (tall-deck)
10114184	427		1991-1992	Two-bolt or four-bolt
14015445	454		1978-1987	Two-bolt or four-bolt

BBC Oval Port Cylinder Head Casting Numbers

Number	Engine Size	Year	Combustion Chambers
336781	454	1973-1985	Open chamber
346236	454	1975-1978	Open chamber ("peanut" ports)
353049	454	1970-1973	Open chamber
3872702	396 and 427	1966	Closed chamber
3904390	427	1966	Closed chamber
3904390	427	1966	Closed chamber
3909802	396 and 427	1966-1967	Closed chamber
3917215	396 and 427	1966-1969	Closed chamber
3931063	396 and 427	1966-1969	Closed chamber
3964280	427 and 454	1966-1970	Closed chamber
3964290	427 and 454	1966-1970	Closed chamber
3993820	402 and 454	1970-1971	Open chamber
3999241	402	1970-1972	Open chamber
6272292	402 and 454	1971	Open chamber

BBC Rectangular Port Cylinder Head Casting Numbers

Number	Engine Size	Year	Combustion Chambers
3856208	396	1965	Closed chamber
3904391	396 and 427	1965-1967	Closed chamber
3919840	396 and 427	1965-1969	Closed chamber
3964291	396, 402, and 427	1965-1970	Closed chamber
3964292	454	1970	Closed chamber
3994025	454	1971	Open chamber
3994026	454	1971	Open chamber
3996074	454	1971	Open chamber
6258723	454	1971	Open chamber
6272990	454	1971	Open chamber

Big Block Chevy Valve Covers

Here are some of the cast aluminum big block Chevy valve covers that I've collected over the years.

Among the very first aftermarket valve covers for the 396 and 427 engines were these from Cal Custom, in Gardena, California. These were die-cast parts that were high-quality and very popular. The early versions say "Gardena, Calif. No. 40-2100". The later versions say "Carson, Calif. No. 4701-4028". The only difference is in the logo, which is on the breather knock-out.

These were one of very few aftermarket valve covers to have oil drippers located above the rocker arms. Although Cal Custom made valve covers for many different engines, the big block Chevy version was the only one that I know of, and the only aftermarket big block Chevy valve covers that I know of other than Edelbrock, that had drippers.

Edelbrock has made several different styles of cast aluminum valve covers for the big block Chevy, and this pair is one of the earliest.

Another cast-aluminum Edelbrock valve cover for big block Chevy engines was similar to these but with a curved Edelbrock logo.

A third version was essentially a Mickey Thompson valve cover with the Edelbrock name on it, along with a mirror-imaged Chevy bow-tie logo.

Error! Bookmark not defined.These sand-cast Keith Black valve covers were made in the late 1970s and early 1980s.

Although KB has made several styles of their own breathers, the pair shown here has been fitted with aftermarket "no-name" breathers.

This is a rare pair of die-cast aluminum valve covers that were made in the 1990s by Advance Marine in Monrovia, California.

The tops of these are angled like many Ford valve covers.

The Advance Marine valve covers were good die castings, with clearance for virtually any rocker arms.

More Big Block Chevy Engine Resources

Big Block Chevy Engine Parts Identification
Mike Maciolek has put together a site that is packed with information about engine codes for both rats and mice.
http://www.nastyz28.com/bbcmenu.html

Big Block Chevy Engine Projects
This page describes the engines that I'm building for my roadster and for my coupe.
http://www.roadsters.com/power/

MorTec, Inc.
The creators of "Engine Math For The Rest Of Us" software provide a great deal of information on their site, including Chevy bore and stroke, casting numbers and their locations, and crank journal sizes.
http://www.mortec.com/

http://www.roadsters.com/