Big Block Chevy engine numbers

0-326711.....................4-bolt, Alum., CanAm, 4.44" bores, steel cylinder liners
340220.....427T......68-85...4-bolt
345014.....454.......70-86...
346236.....454.......75-76...2-bolt
359070.....454.......70-90...
361959.....454.......73-90...2 or 4 bolt
364776.....427T......68-85...4-bolt
364779.....366T......68-90...4-bolt
399204.....509.......70-71...4-bolt, Alum., CanAm, 4.5" bores, steel Cylinder liners
399293.....366T......77-78...4-bolt
473478.....427T......77-90...4-bolt
495102.......................4-bolt, Alum., CanAm, 4.5" bores
3782870....427T......68-76...4-bolt
3824553....366T......66-67...4-bolt
3855961....396.......65-66...2 or 4 bolt
3855961....427.......66......2-bolt
3855962....396.......65-66...4-bolt
3855977....366T......66-73...4-bolt
3869942....427.......66-67...2 or 4 bolt
3902406....396.......67......2 or 4 bolt
3904351....427.......67......2 or 4 bolt
3904354....366T......66-76...4-bolt
3916319....366T......68......4-bolt
3916321....427.......68......2 or 4 bolt
3916323....396.......68......2 or 4 bolt
3925521....427T......68-85...4-bolt
3935439....427.......68-69...2 or 4 bolt
3935440....396.......68-69...2 or 4 bolt
3937724....366T......68-85...4-bolt
3937726....427T......68-84...4-bolt
3946052....427.......69......4-bolt, Alum. ZL-1, Mark IV
3946053....427.......97-up...4-bolt, Alum. ZL-1, 2nd version, Mark IV
3955270....427.......69......2 or 4 bolt
3955272....396.......69......2 or 4 bolt
3955274....366T......68-85...4-bolt
3955276....427T......68-73...4-bolt
3963512....427.......69......2 or 4 bolt
3963512....454.......70-76...2 or 4 bolt
3969852....366T......68-84...4-bolt
3969854....396.......69......2 or 4 bolt
3969854....402.......70-72...2 or 4 bolt
3969858....427T......68-84...4-bolt
3999289....454.......71-79...2 or 4 bolt, some "CE" replacement blocks had four bolt main caps
3999290....396.......68-69...2 or 4 bolt, Truck
3999290....402.......70-72...2 or 4 bolt, Truck
3999290....402.......72......2 or 4 bolt, Passenger
3999293....366T......68-90...4-bolt
3999294....427T......68-84...4-bolt
10051107...454...............4-bolt, Bowtie, MkIV, 9.8" deck, siamesed bores, 4.25" semi-finished bores, can be bored to 4.50"
10069282...366T......90-91...4-bolt, Mark IV, Tall deck
10069284...427T..............4-bolt, Mark IV, Tall deck
10069286...454.......90-91...4-bolt, Mark IV, Short deck
10114182...454.......91-up...4-bolt, Gen.V
10114183...366T......91-up...4-bolt, Gen.V
10114184...427T......91-up...4-bolt, Gen.V
10134366...454T..............4-bolt, Bowtie, Gen.V, Tall deck
10185050...454...............4-bolt, Bowtie, Gen.V, Short deck
10237297...454.......96-up...4-bolt, Vortec 7400", "L-29" Gen.VI
10237299...427T......96-up...4-bolt, Gen.VI, 7.0L, truck
10237300...502.......96-up...4-bolt, Gen.VI, 4.466" bore
12550312...427T......96-up...4-bolt, Gen.VI, 4.250" bore, fuel pump boss, clutch linkage pivot boss
12550313...454.......91-up...4-bolt, Gen.V crate motor, Gen. VI 4.25" bare block, fuel pump boss
12556110...496.......01-up...4-bolt, Gen.VII 8.1L, "Vortec 8100", Truck
12561357...454.......96-up...4-bolt, Gen.VI
12561358...502...............4-bolt, Gen. VI
14015443...454.......87-90...2 or 4-bolt, Mark IV, Truck, Motorhome
14015445...454.......78-90...2 or 4 bolt
14044807...454T..............4-bolt, Bowtie, MkIV, CNC prep, Tall deck, 4.25" bore or 4.495" bores
14096859...502...............4-bolt, Gen.V, HO
24502504...454...............4-bolt, Bowtie, Gen.V, Race prep, 9.8 "short" deck height
24502506...454T..............4-bolt, Bowtie, Gen.V, Race prep, 10.2 "tall" deck height
24502572.....................4-bolt, 4.5" bore Olds DRCE 2, 9.5" deck height
25534402.....................4-bolt, 4.590" bore Olds DRCE 3, 9.25" deck height


T = Tall deck, 10.2" deck height

1991 and later Gen.V, VI and VII production BBC motors have one-piece rear main crank seals.