The Chevrolet small-block engine is a series of automobile V8 engines built by the Chevrolet Division of General Motors using the same basic, and for a V8, smaller engine block. These blocks are referred to as either the “Gen I” small block, the subsequent “Gen II” LT, and “Generation III/IV” LS, along with the current “Generation V” (LT/EcoTec3) engines. Chevrolet had introduced its popular small-block V8 in 1955 but needed something larger to power the medium-duty trucks and its heavier cars that were on the drawing board. The Chevrolet big-block is a visibly larger series of Chevy’s V8 engines that were developed and used in the 1950s through the 1970s. Many engine blocks of the same generation look alike. Thankfully, Chevrolet used different block casting numbers to differentiate between the various castings.
Small-Block Chevy V8 Engines
This drawing is of the 1967 version of the 302 cid Chevrolet as drawn by David Kimble. Production of the first-generation small-block began in the fall of 1954, for the 1955 model year. Production started with a displacement of 265 cubic inches and grew incrementally over time until reaching 400 cubes in 1970. Several intermediate displacements appeared over the years, such as the 283 cubic inch engine that was available with mechanical fuel injection, the 327 variant, and the numerous 350 cid versions.
Although all of Chevrolet’s siblings of the period (Buick, Cadillac, Oldsmobile, and Pontiac) designed their own V8s, it was the Chevrolet 350 cubic inch (5.7 L) small-block that became the GM corporate standard. Over the years, every American General Motors division, except Saturn, used it and its descendants in their vehicles.
In all, over 90,000,000 small-block engines have been built in both carbureted and fuel-injected forms since 1955. The small-block family line was honored as one of the 10 Best Engines of the 20th Century by the automotive magazine Ward’s AutoWorld.
Here is a list of casting numbers, along with their original applications.
Chevy’s First-Generation Small-Block V8 Casting Numbers
10036033 Small Block V8 350, 4-bolt, Goodwrench crate engine, 2-piece rear seal
10051182 Small Block V8 2 bolt, Bow Tie block, 3.75-4.30 bore, 1-piece rear seal
10051184 Small Block V8 4 bolt, Bow Tie, 4.00-4.160 bore, 1-piece rear seal
10054727 Small Block V8 1986 350, 2-bolt or 4-bolt, one-piece rear seal
10066036 Small Block V8 350, 4-bolt, Goodwrench crate engine, 2-piece rear seal
10066038 Small Block V8 1994 350, 4-bolt, Goodwrench crate engine, 2-piece rear seal
10090511 Small Block V8 1990 350, 2-bolt, LT5, Corvette ZR1, 375hp
10134996 Small Block V8 4-bolt, Bow Tie, aluminum, 4.125 bore, 2.65 main journals
10199001 Small Block V8 1993-1995 350, 4-bolt, LT5, Corvette ZR1, 405 hp
10243878 Small Block V8 1996-1997 305, 2-bolt, Vortec truck, roller cam, 1-piece rear seal
10243880 Small Block V8 1995-1999 350, 4 bolt, crate engines and ZZ4, roller cam, one-piece rear seal
140029 Small Block V8 1980-1984 350, 2 bolt
14010201 Small Block V8 1980-1984 305, 2 bolt
14010202 Small Block V8 1980-1984 305, 2 bolt
14010203 Small Block V8 1980-1985 305, 2 bolt
14010207 Small Block V8 1980-1985 350, 2 bolt or 4 bolt
14010209 Small Block V8 1980-1985 350, 4 bolt
14010280 Small Block V8 1979-1982 267, 2 bolt
14011064 Small Block V8 1983 350, 4 bolt
14011148 Small Block V8 1987-1989 350, roller cam, 1-piece rear seal
14016376 Small Block V8 1979-1982 267, 2 bolt
14016379 Small Block V8 1977-1979 350, 2 bolt or 4 bolt
14016381 Small Block V8 1980-1984 305, 2 bolt
14016382 Small Block V8 1979-1984 305, 2 bolt
14079287 Small Block V8 1986-1990 350, Truck
14088526 Small Block V8 1987-1989 350, roller cam, 1-piece rear seal
14088548 Small Block V8 1986-1988 350, 2 bolt or 4 bolt
14088551 Small Block V8 1986-1987 305, 2 bolt, 1-piece rear main seal
14093627 Small Block V8 1987-1991 305, 2 bolt, roller cam, 1-piece rear seal
14093638 Small Block V8 1987-1995 350, 2 bolt or 4 bolt, roller or flat tappet cam, 1-piece rear seal
14101148 Small Block V8 1987-1990 350, 4 bolt, 1-piece rear seal
14102058 Small Block V8 1987-1991 305, 2 bolt, roller cam, 1-piece rear seal
330817 Small Block V8 1972-1980 400, 2 bolt
3556519 Small Block V8 1958-1961 283, 2 bolt
355909 Small Block V8 1975 262, 2 bolt
355909 Small Block V8 1976-1979 305, 2 bolt
360851 Small Block V8 1975-1976 262, 2 bolt
361979 Small Block V8 1978-1979 305, 2 bolt
366245 Small Block V8 1978-1979 350, 2 bolt
3703524 Small Block V8 1955 265, 2 bolt, no oil filter
3720991 Small Block V8 1956-1957 265, 2 bolt
3731548 Small Block V8 1957 265, 2 bolt, no side engine mounts
3731548 Small Block V8 1957 283, 2 bolt, no side mounts
3737739 Small Block V8 1958-1964 283, 2 bolt
3756519 Small Block V8 1958-1962 283, 2 bolt
3782870 Small Block V8 1962-1967 327, 2 bolt
3789817 Small Block V8 1962-1964 283, 2 bolt
3789817 Blocks Small Block V8 1962-1967 327, 2 bolt
3789935 Small Block V8 1961-1964 283, 2 bolt
3790721 Small Block V8 1962-1964 283, 2 bolt, recessed oil filter boss
3790721 Small Block V8 1965-1966 327, 2 bolt, recessed oil filter boss
3791362 Small Block V8 1962-1967 327, 2 bolt, recessed oil filter boss
3792563 Small Block V8 1965 327, 2 bolt
3792582 Small Block V8 1964-1965 283, 2 bolt
3794226 Small Block V8 1958-1963 283, 2 bolt
3794460 Small Block V8 1962-1964 327, 2 bolt
3814660 Small Block V8 1968-1969 327, 2 bolt
3830944 Small Block V8 1963 327, 2 bolt
3834810 Small Block V8 1964-1966 283, 2 bolt
3834812 Small Block V8 1962-1963 283, 2 bolt
3837739 Small Block V8 1958-1962 283, 2 bolt
3849852 Small Block V8 1957-1966 283, 2 bolt
3849935 Small Block V8 1965-1967 283, 2 bolt
3858174 Small Block V8 1964-1967 327, 2 bolt
3858180 Small Block V8 1964-1967 327, 2 bolt
3858618 Small Block V8 1968-1976 350, 2 bolt
3862194 Small Block V8 1965-1967 283, 2 bolt, recessed oil filter boss
3862812 Small Block V8 1962-1964 283, 2 bolt
389257 Small Block V8 1967 302, 2 bolt
3892657 Small Block V8 1967 302, 2 bolt, Camaro Z28
3892657 Small Block V8 1967 327, 2 bolt
3892657 Small Block V8 1967 302, 2 bolt, Camaro Z28
3896944 Small Block V8 1967 283, 2 bolt
3896948 Small Block V8 1966-1967 283, 2 bolt
3903352 Small Block V8 1967 327, 2 bolt
3914636 Small Block V8 1968 307, 2 bolt
3914653 Small Block V8 1968-1973 307, 2 bolt
3914660 Small Block V8 1968 327, 2 bolt
3914678 Small Block V8 1968 302, 2 bolt, Camaro Z28
3914678 Small Block V8 1968 327, 2 bolt
3914678 Small Block V8 1968 350, 2 bolt
3932371 Small Block V8 1969-1973 307, 2 bolt
3932373 Small Block V8 1968-1973 307, 2 bolt
3932386 Small Block V8 1969 302, 4 bolt, Camaro Z28
3932386 Small Block V8 1969 327, 2 bolt
3932386 Small Block V8 1969 350, 4 bolt
3932388 Small Block V8 1969 350, 2 bolt or 4 bolt
393288 Small Block V8 1965-1967 283, 2 bolt
3951509 Small Block V8 1970-1971 400, 4 bolt
3951509 Small Block V8 1974-1980 400, 2 bolt
3951511 Small Block V8 1970-1972 400, 2 bolt or 4 bolt
3956618 Small Block V8 1969 302, 4 bolt, Camaro Z28
3956618 Small Block V8 1968-1969 327, 2 bolt
3956618 Small Block V8 1969 350, 2 bolt or 4 bolt
3956632 Small Block V8 1969 307, 2 bolt
3959512 Small Block V8 1962-1963 327, 2 bolt
3970010 Small Block V8 1969 302, 4 bolt, Camaro Z28
LS-Based Small Block Casting Numbers
12550592 LS Small Block V8 1997-up 346, LS1
12559846 LS Small Block V8 1998-up 346, LS1
12560621 LS Small Block V8 1998-up 346, LS1
12562174 LS Small Block V8 1998-up 346, LS1
LT-Based Small Block Casting Numbers
10125327 LT Small Block V8 1992 350, 2 bolt or 4 bolt, LT1, reverse flow cooling
10125327 LT Small Block V8 1996 350, 2 bolt or 4 bolt, LT4, reverse flow cooling
10153558 LT Small Block V8 1991-1992 350, 4 bolt, LT5, Corvette ZR1, 375hp
“W” Block Casting Numbers
3732755 W Block 1959-1961 348 CID
3732811 W Block 1958 348 CID
3751872 W Block 1958 348 CID
3755011 W Block 1959-1961 348 CID
3771705 W Block 1959-1961 348 CID
3782012 W Block 1958-1961 348 CID
3788068 W Block 1962-1963 409 CID
3795623 W Block 1961 409 CID
3798962 W Block 1962-1965 348 CID, Truck
3815707 W Block 1958-1961 348 CID
3830814 W Block 1963 427 CID, Z11, 4.312-inch bore, 3.65-inch stroke
3830814 W Block 1963-1964 409 CID
3839752 W Block 1962-1963 409 CID
3839754 W Block 1965 409 CID
3844422 W Block 1963-1965 409 CID
3857655 W Block 1962-1965 348 CID, Truck
3857656 W Block 1964-1965 409 CID
3860386 W Block 1962-1964 409 CID
3860387 W Block 1958 348 CID
3844422 W Block 1963-1965 409 CID
3857655 W Block 1962-1965 348 CID, Truck
3857656 W Block 1964-1965 409 CID
3860386 W Block 1962-1964 409 CID
3860387 W Block 1958 348 CID
Big Block Casting Numbers
10051107 Big Block V8 454, 4 bolt, Bowtie, MkIV, 9.8 deck, siamese bores, 4.25-4.50 bore
10069282 Big Block V8 1990-1991 366 tall deck, 4 bolt, Mark IV, Tall deck
10069284 Big Block V8 427 tall deck, 4 bolt, Mark IV, Tall deck
10069286 Big Block V8 1990-1991 454, 4 bolt, Mark IV, Short deck
10114182 Big Block V8 1991+ 454, 4 bolt, Generation V
10114183 Big Block V8 1991+ 366 tall deck, 4 bolt, Generation V
10114184 Big Block V8 1991+ 427 tall deck, 4 bolt, Generation V
10134366 Big Block V8 454 tall deck, 4 bolt, Bowtie, Generation V, Tall deck
10185050 Big Block V8 454, 4 bolt, Bowtie, Generation V, Short deck
10237297 Big Block V8 1996+ 454, 4 bolt, Vortec 7400, L-29 Generation VI
10237299 Big Block V8 1996+ 427 tall deck, 4 bolt, Generation VI, 7.0L, truck
10237300 Big Block V8 1996+ 502, 4 bolt, Generation VI, 4.466 bore
12550312 Big Block V8 1996+ 427 tall deck, 4 bolt, Generation VI, 4.250 bore, fuel pump boss, clutch linkage pivot boss
12550313 Big Block V8 1991+ 454, 4 bolt, Generation V crate motor, Generation VI 4.25 bare block, fuel pump boss
12556110 Big Block V8 2001+ 496, 4 bolt, Generation VII 8.1L, Vortec 8100, Truck
12561357 Big Block V8 1996+ 454, 4 bolt, Generation VI
12561358 Big Block V8 502, 4 bolt, Generation VI
14015443 Big Block V8 1987-1990 454, 2 or 4 bolt, Mark IV, Truck or Motorhome
14015445 Big Block V8 1978-1990 454, 2 bolt or 4 bolt
14044807 Big Block V8 454 tall deck, 4 bolt, Bowtie, MkIV, CNC prep, Tall deck, 4.25 bore or 4.495 bores
14096859 Big Block V8 502, 4 bolt, Generation V, HO
24502504 Big Block V8 454, 4 bolt, Bowtie, Generation V, Race prep, 9.8 short deck height
24502506 Big Block V8 454 tall deck, 4 bolt, Bowtie, Generation V, Race prep, 10.2 tall deck height
24502572 Big Block V8 4 bolt, 4.5 bore Olds DRCE 2, 9.5 deck height
25534402 Big Block V8 4 bolt, 4.590 bore Olds DRCE 3, 9.25 deck height
326711 Big Block V8 4 bolt, aluminum, CanAm, 4.44 bores, steel cylinder liners
340220 Big Block V8 1968-1985 427 tall deck, 4 bolt
345014 Big Block V8 1970-1986 454,
346236 Big Block V8 1975-1976 454, 2 bolt
359070 Big Block V8 1970-1990 454,
361959 Big Block V8 1973-1990 454, 2 bolt or 4 bolt
364776 Big Block V8 1968-1985 427 tall deck, 4 bolt
364779 Big Block V8 1968-1990 366 tall deck, 4 bolt
3782870 Big Block V8 1968-1976 427 tall deck, 4 bolt
3824553 Big Block V8 1966-1967 366 tall deck, 4 bolt
3855961 Big Block V8 1965-1966 396, 2 bolt or 4 bolt
3855961 Big Block V8 1966 427, 2 bolt
3855962 Big Block V8 1965-1966 396, 4 bolt
3855977 Big Block V8 1966-1973 366 tall deck, 4 bolt
3869942 Big Block V8 1966-1967 427, 2 bolt or 4 bolt
3902406 Big Block V8 1967 396, 2 bolt or 4 bolt
3904351 Big Block V8 1967 427, 2 bolt or 4 bolt
3904354 Big Block V8 1966-1976 366 tall deck, 4 bolt
3916319 Big Block V8 1968 366 tall deck, 4 bolt
3916321 Big Block V8 1968 427, 2 bolt or 4 bolt
3916323 Big Block V8 1968 396, 2 bolt or 4 bolt
3925521 Big Block V8 1968-1985 427 tall deck, 4 bolt
3935439 Big Block V8 1968-1969 427, 2 bolt or 4 bolt
3935440 Big Block V8 1968-1969 396, 2 bolt or 4 bolt
3937724 Big Block V8 1968-1985 366 tall deck, 4 bolt
3937726 Big Block V8 1968-1984 427 tall deck, 4 bolt
3946052 Big Block V8 1969 427, 4 bolt, aluminum ZL-1, Mark IV
3946053 Big Block V8 1997+ 427, 4 bolt, aluminum ZL-1, 2nd version, Mark IV
3955270 Big Block V8 1969 427, 2 bolt or 4 bolt
3955272 Big Block V8 1969 396, 2 bolt or 4 bolt
3955274 Big Block V8 1968-1985 366 tall deck, 4 bolt
3955276 Big Block V8 1968-1973 427 tall deck, 4 bolt
3963512 Big Block V8 1969 427, 2 bolt or 4 bolt
3963512 Big Block V8 1970-1976 454, 2 bolt or 4 bolt
3969852 Big Block V8 1968-1984 366 tall deck, 4 bolt
3969854 Big Block V8 1969 396, 2 bolt or 4 bolt
3969854 Big Block V8 1970-1972 402, 2 bolt or 4 bolt
3969858 Big Block V8 1968-1984 427 tall deck, 4 bolt
399204 Big Block V8 1970-1971 509, 4 bolt, aluminum, CanAm, 4.5 bores, steel Cylinder liners
399293 Big Block V8 1977-1978 366 tall deck, 4 bolt
3999289 Big Block V8 1971-1979 454, 2 bolt or 4 bolt, some CE replacement blocks had four-bolt main caps
3999290 Big Block V8 1968-1969 396, 2 bolt or 4 bolt, Truck
3999290 Big Block V8 1970-1972 402, 2 bolt or 4 bolt, Truck
3999290 Big Block V8 1972 402, 2 bolt or 4 bolt, Passenger
3999293 Big Block V8 1968-1990 366 tall deck, 4 bolt
3999294 Big Block V8 1968-1984 427 tall deck, 4 bolt
473478 Big Block V8 1977-1990 427 tall deck, 4 bolt
495102 Big Block V8 4 bolt, aluminum, CanAm, 4.5 bores