Small Block Chevy Block Casting Numbers

The block casting number on small block and big block Chevy V-8 motors is located on a ledge found at the rear of the block, most often on the driver’s side. This ledge is below the deck of the block and the ledge forms the mating surface between the block and the transmission bell housing. Some of the later model blocks have the casting number on the passenger side of this ledge.

The number itself can have 6, 7 or 8 numeral digits. They might look like this “361959” or “3970010” or “14015445”. The block casting numbers do not have any letters in them. There are sometimes other individual letters found on blocks like “GM” or “CFD” for the Central Foundry Division, but they are not part of the block casting number. Also some of the later blocks have the size of the motor shown in liters. You may see a “5.0” (305) or “5.7” (350) cast on the rear ledge of a small block or a “7.4” on the side of a big block 454.

On the side of some later blocks the last three digits of the block casting number are cast into the block, but these are difficult to see when the engine is in a vehicle.

SBC Casting Numbers and Applications
Casting
Number
Year CID Main
Bolts
Notes
140029 80-84 350 2  
330817 70-80 400 2  
355909 75 262 2  
355909 76-79 305 2  
360851 75-76 262 2 Monza V-8
361979 77-79 305 2 or 4 Some Canadian assembled heavy duty blocks have 4-bolt main caps.
366245 78-82 350 4 Bowtie High Tin
366286/7   350 4 Bowtie, Aluminum, siamesed, straight nodular iron main caps 2-piece seal, 4.00-4.150 bores, 2.45 main journals
366298     4 Bowtie, Aluminum, billet main caps,3.398 bore with sleeves, 2 piece rear seal
366299   350 4 Bowtie Aluminum nodular iron splayed caps wet sump 4.00 bore
389257 67 302 2  
393288 65-67 283 2  
460703 78 350 4  
460776 78-79 305 2  
460777 78-79 305 2  
460778 78-79 305 2 or 4 Some Canadian assembled heavy duty truck blocks have 4-bolt main caps
471511 79-82 267 2  
3556519 58-61 283 2  
3703524 55 265 2 No oil filter
3720991 56-57 265 2  
3731548 57 265 or 283 2 No side motor mounts
3737739 58-64 283 2  
3737739 57-62 283 only 2  
3756519 58-62 283 2  
3782870 62-67 327 2  
3789817 62-64 283 or 327 2  
3789935 61-64 283 2  
Casting
Number
Year CID Main
Bolts
Notes
3790721 62-64 283 2 Chevy II recessed oil filter boss
3790721 65-66 327 2 Chevy II recessed oil filter boss
3791362 62-67 327 2 Chevy II recessed oil filter boss
3792563 65 327 2  
3792582 64-65 283 2  
3794226 58-63 283 2  
3794460 62-64 327 2  
3814660 68-69 327 2  
3830944 63 327 2  
3834810 64-66 283 2  
3834812 62-63 283 2  
3837739 58-62 283 2  
3849852 64-68 283 2  
3849935 65-67 283 2 Truck
3852174 62-64 327 2  
3858174 64-66 327 2  
3858180 64-67 327 2  
3858618 68-76 350 2  
3862194 65-67 283 2 Chevy II recessed oil filter boss
3862812 62-64 283 2  
3892657 67 302 2 Z-28 Camaro, small journal
3892657 67 327 2  
3892657 67 350 2 Camaro
3892657 64-67 350 327 & 302 2  
3896944 67 283 2  
3896948 66-67 283 2  
3903352 67 327 2  
3914636 68 307 2  
3914653 68-73 307 2  
3914660 68 327 2  
3914678 68 327 2  
3914678 68 302 2 Z-28 Camaro
3914678 68 350 2  
3932371 69-73 307 2  
3932373 68-73 307 2  
3932386 69 302 4 Z-28 Camaro
3932386 69 350 4  
3932388 69 350 4  
3951509 70-80 400 only 2 or 4  
3951509 74-75 400 2  
3951509 70-71 400 4  
3951511 70 – 80 400 only 2 or 4  
Casting
Number
Year CID Main
Bolts
Notes
3951511 70-71 400 2 or 4 Some replacement blocks had 2-bolt main caps
3956618 69 350 2 or 4  
3956618 68-69 327 2  
3956618 69 302 4 Z-28 Camaro
3956632 69 307 2  
3959512 62-67 327 2 Was also used for some CE replacement blocks
3959532 64 283 2 Was also used for some CE replacement blocks
3959538 327 2 Chevy II recessed oil filter boss, Used for some Chevy II CE replacement blocks
3970010 69 302 4 Z-28 Camaro
3970010 69-80 327 2 Trucks and industrial
3970010 69-79 350 only 2 or 4  
3970014 70-72 350 2 or 4

Camaro

3970014 68-79 350    
3970020 69-73 307 2  
3970024 69-73 307 2  
4715111 80 305 2  
6259425 69-76 350 2  
10036033   350 4 Goodwrench crate motor 2-piece rear seal "Hecho en Mexico"
10046164 86 305 2  
10049804     4 Aluminum, Pontiac Super Duty version of Gen.I SBC, 4.00 bore,
350 mains, 2-piece rear seal, splayed caps, GTP race block
10051182     2 or 4 Bowtie, 3.75-4.30 bores, 1 or 2-piece rear seal
10051184     4 Bowtie, 4.00-4.155 bores, 1 or 2-piece rear seal
10054727 86-up 350 2 or 4 one piece rear seal, some Made in Canada
10066036 94 350 2 or 4 Target Master/Goodwrench crate motor, 2-piece rear
seal, Hecho en Mexico
10066038 94 350 4 Goodwrench crate motor, 2-piece rear seal, "Hecho en Mexico"
Casting
Number
Year CID Main
Bolts
Notes
10090511 90 350 2 LT-5, ZR1 Vette 375hp
10125327 96-up 350 2 or 4 Gen.II LT-4 reverse flow cooling
10125327 92-up 350 2 or 4 Gen.II LT-1 reverse flow cooling
10134398     4 Bowtie Aluminum 4.125 bore, 2.65 main journals
10134996     4 Bowtie Aluminum 4.125 bore 2.65 main journals
10153558 91-92 350 4 LT-5 ZR1 Vette 375hp
10168588 94-96 265 2 L99, Gen.II, 4.3 Liter V-8, Caprice, reverse flow cooling
10199001 93-95 350 4 LT-5 ZR1 Vette 405hp
10243878 96-98 305 2 Vortec truck, roller cam, one-piece rear seal
10243880 95-00 350 2 or 4 Vortec truck, Gen.I crate motors and ZZ4, roller cam, one piece rear seal
12550592 97-up 350   crossbolted block, Gen.III, LS1, aluminum
12551358 99-up 4.8 or 5.3   Gen.III, 4.8L or 5.3L, cast iron, truck
12551364 99-up 364   crossbolted cast iron Gen. III, 6.0L, truck
12559378 99-up 350   crossbolted block, Gen.III, LS1, aluminum
12559846 98-up 350   crossbolted block, Gen.III, LS1, aluminum
12560621 98-up 350   crossbolted block, Gen.III, LS1, aluminum
12560626 99-up 350   crossbolted block, Gen.III, LS1, aluminum
12560629 99 350   crossbolted block, Gen.III, LS1, aluminum
12561168 01-up 350   crossbolted block, Gen.III, LS1, aluminum
12562174 98-up 350   crossbolted block, Gen.III, LS1, aluminum
12568952 05-up 364   crossbolted block, Gen.III, 6.0L, aluminum, LS2
12566910 04-up 325   crossbolted block, Gen.III, 5.3L, aluminum, SSR truck
12571048 04-up 325   crossbolted block, Gen.III, 5.3L
1253581 98-04 364   crossbolted cast iron, Gen.III, 6.0L, truck
12577184 98-04 364   crossbolted cast iron, Gen.III, 6.0L, truck
12577396 02-up     Gen.III, 4.8L or 5.3L, cast iron, truck
Casting
Number
Year CID Main
Bolts
Notes
14010201 80-84 305 2  
14010202 80-84 305 2  
14010203 80-84 305 2  
14010207 80-85 350 2 or 4 Truck
14010209 80-85 350 4 Truck
14010280 79-82 267 2  
14011064 83 350 4  
14011064 82-86 350 4 4-Bolt main Bowtie High Tin
14011064 83 350    
14011148 87-89 350   Roller cam one-piece rear seal
14016376 79-82 267 2  
14016379 77-79 350 2 or 4  
14016381 80-84 305 2  
14016382 79-84 305 2  
14016383 80-85 305 2 Truck
14079287 86-90 350   Truck
14088526 86-88 350 2 or 4 1 piece rear main seal.
14088584 86-88 350 2 or 4  
14088551 86-87 305 2 one-piece rear seal
14093627 87-94 305 2 Roller or flat tappet cam one-piece rear seal
14093638 87-95 350 2 or 4 Roller or flat tappet cam, one-piece rear seal.
14094766 86-up 305 2 One-piece rear seal
14101147 85-up 305 2  
14101148 86-90 350 4 1 piece rear main seal.
14102058 87-91 305 2 Roller cam, one-piece rear seal
22551656     4 Chevy/Olds Rocket block, 4.00-4.190 bores, 2.45 main
journal sizes, splayed caps, dry sump,
2-piece rear seal, 9.025 deck
22551660     4 Chevy/Olds Rocket block, 4.00-4.190 bores, 400 mains
journal sizes, splayed steel caps, wet sump, raised cam
2-piece rear seal, 9.300 deck
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2 thoughts on “Small Block Chevy Block Casting Numbers

    • Thanks for looking.That is in the listing as a Gen II/IV LT1 reverse flow block. Pretty much a vanilla LT1 92 and up unit. The key here is reverse flow. Could be any application with an LT1 option. Mostly passenger cars but some light trucks. Designed for serpentine drive. Hope this helps. Bob

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