BIG BLOCK CHEVROLET BLOCK CASTING #'S
CASTING# YEAR CID MAINS NOTES
326711     4 4.44" bores, aluminum block, steel cylinder liners
340220 68-85 427T 4  
345014 70-86 454    
346236 75-76 454 2  
359070 70-90 454    
361959 73-90 454 2 or 4  
364776 68-85 427T 4  
364779 68-90 366T 4  
399204 70-71   4 4.5" bores, aluminum block, steel cylinder liners
399293 77-78 366T 4  
473478 77-90 427T 4  
495102     4 4.5" bores, aluminum block, steel cylinder liners
3782870 68-76 427T 4  
3824553 66-67 366T 4  
3855961 65-66 396/427 2 or 4  
3855962 65-66 396 4  
3855977 66-73 366T 4  
3869942 66-77 427 2 or 4  
3902406 67 396 2 or 4  
3904351 67 396 2 or 4  
3904354 66-76 366T 4  
3916319 68 366T 4  
3916321 68 427 2 or 4  
3916323 68 396 2 or 4  
3925521 68-85 427T 4  
3935439 68-69 427 2 or 4  
3935440 68-69 396 2 or 4  
3937724 68-85 366T 4  
3937726 68-84 427T 4  
3946052 69 427 4 ZL1, aluminum block, Mark IV
3946053 97-P 427 4 ZL1, aluminum block, Marv IV, 2nd version
3955270 69 427 2 or 4  
3955272 69 396 2 or 4  
3955274 68-85 366T 4  
3955276 68-73 427T 4  
3963512 70-76 454 2 or 4  
3969852 68-84 366T 4  
3969854 69-72 396/402 2 or 4 69 396, 70-72 402
3969858 68-84 427T 4  
3999289 68-84 454 2 or 4  
3999290 68-72 396/402 2 or 4 68-69 396 truck, 70-72 402 truck, 72 402 passenger car
3999293 68-90 366T 4  
3999294 68-84 427T 4  
10051107   454 4 Bowtie Mark IV Block, 9.8" Deck, Siamesed, 4.25" bores, 4.5" max
10069282 90-91 366T 4 Mark IV
10069284   427T 4 Mark IV
10069286 90-91 454 4 Mark IV
10114183 91-P 366T 4 Gen V
10114184 91-P 427T 4 Gen V
10134366   454T 4 Bowtie Gen V
10185050   454 4 Bowtie Gen V
10237297 96-P 454 4 L29 Gen VI, Vortec 7400
10237299 96-P 427T 4 Gen VI, 7.0L truck
10237300 96-P 502 4 Gen VI, 4.466" Bore
12550312 96-P 427T 4 Gen VI w/fuel pump and z-bar boss, 4.25" bore
12550313 91-P 454 4  
12556110 01-P 496 4 Gen VII, Vortec 8100 Truck
12561357 96-P 454 4 Gen VI
12561358   502 4 Gen VI
14015443 89-90 454 2 or 4 Mark IV, truck/motor home
14015445 78-90 454 2 or 4  
14044807   454T 4 Bowtie Mark IV, 4.25"/4.50" max
14096859   502 4 Gen V, HO
24502504 GMPP 454 4 Bowtie Gen V, Race Prepped
24502506 GMPP 454T 4 Bowtie Gen V, Race Prepped
24502572 GMPP   4 Olds DRCE 2, 9.5" deck, 4.5" bore
25534402 GMPP   4 Olds DRCE 3, 9.25" deck, 4.590 bore

T=Tall deck block (10.2" deck), 1991-later Gen V, VI and VII production BBC engines use a 1-pc rear main seal and crankshaft

 

BIG BLOCK CHEVROLET CYLINDER HEAD CASTING #'S
CASTING YEAR PORT CHAMBER NOTES
330864 68-84 OVAL OPEN 396, 402, 366T, 427T, 454 Truck
330865 68-84 OVAL OPEN 396, 402, 366T, 427T, 454 Truck
330866 68-78 OVAL OPEN 366T, 427T
330867 68-73 OVAL OPEN 427T
336765 68-78 OVAL OPEN 427T
336768 73-76 OVAL OPEN 427T
336781 73-85 OVAL OPEN 454, 118cc chamber, 256/114cc ports
343771 68-86 OVAL OPEN 366T, 427T, 454
343772 68-86 OVAL OPEN 366T, 427T, 454
343783 70-76 OVAL OPEN 454 Truck
346236 75-87 OVAL OPEN 454, 120cc chamber, 225/116cc ports
352625 70-76 OVAL OPEN 454 Truck
353049 73-84 OVAL OPEN 454, 122cc chamber, 255/119cc ports
366765 74-78 OVAL OPEN 427T
473328 68-69 OVAL OPEN 366T
3856206 65-66 OVAL CLOSED 396, 97cc chamber
3856208 65 RECT CLOSED 396/425hp, 109cc chamber, 396/375hp Z-16 Chevelle
3856213 66-82 OVAL CLOSED 366T, 427T
3856260 68 OVAL CLOSED 396 Truck
3872702 65-66 OVAL CLOSED 396, 427, 98cc chamber
3873858 65-67 RECT CLOSED 396, 427, 109cc chamber
3876875 77-85 OVAL OPEN 427T
3904390 67 OVAL CLOSED 396, 427, 98cc chamber
3904391 67 RECT CLOSED 396, 427, 107cc chamber
3904392 67 RECT CLOSED 427, Aluminum, L88/L89, 107cc chamber
3904393 68-76 OVAL OPEN 366T
3908952 67 OVAL OPEN 427, truck/marine
3909802 67 OVAL CLOSED 396, 427, 101cc chamber
3917215 67-68 OVAL CLOSED 396, 427, 101cc chamber
3917219 68-85 OVAL OPEN 366T, 427T
3919840 67-69 RECT CLOSED 396, 427, 107cc chamber
3919842 68-69 RECT CLOSED 396, 427, Aluminum L88, L89, 107cc chamber
3931063 68-69 OVAL CLOSED 396, 402, 427, 101cc chamber
3933148 69-84 OVAL OPEN 69 396/265hp, 366T, 427T, 112cc chamber
3933149 68-76 OVAL OPEN 427T, 122cc chamber
3935401 68-76 OVAL OPEN 427T
3946074 69-71 RECT OPEN Aluminum, 118cc chamber, 69 427 L88/ZL1, 71 454 LS6, round exhaust port
3964290 69-70 OVAL CLOSED 396, 402, 427, 454, 101cc chamber, large or small hex spark plugs used
3964291 69-72 RECT CLOSED 396, 402, 427, 454, 109cc chamber, large or small hex spark plugs used
3965198 68-69 OVAL CLOSED 396 Truck
3975950 68-70 OVAL OPEN 396, 402 Truck, 366T, 427T
3986133 68-85 OVAL OPEN 366T, 427T, 454 Truck
3986135 69-73 OVAL OPEN 366T, 427T
3986136 68-84 OVAL OPEN 366T, 427T, 454 Truck
3993820 71-84 OVAL OPEN 71 402, 454, 113cc chamber, 255/114 ports
3994026 71 RECT OPEN 454 LS6, 118cc chamber
3999241 72 OVAL OPEN 402, 454, 113cc chamber
6272292 70-78 OVAL OPEN 402, 454
6272990 70-P RECT OPEN 454, Mark IV crate engines, 118cc chamber
10045427 XXXX RECT XXXX Pontiac/Chevy Aluminum, 91cc chamber, large Port, race
10049875 XXXX RECT XXXX Pontiac/Chevy Aluminum, small port/race
10051128 XXXX RECT XXXX Bowtie, Aluminum, 72cc chambers, symmetrical ports
10051129 XXXX RECT XXXX Bowtie, Aluminum, symmetrical ports
10052902 XXXX OVAL OPEN Mark IV, 427T
10101140 91-P OVAL CLOSED Gen V 366T, 427T
10114156 91-P OVAL OPEN Gen V/VI 454, 118cc chamber
10141279 96-P OVAL CLOSED Vortec 7400, 100cc chambers
10487052 77-90 OVAL OPEN 366T
12363391 96-P OVAL OPEN Bowtie, Aluminum, Signature Series, Mark IV, Gen V/VI, 110cc chamber
12363401 96-P RECT OPEN Bowtie, Aluminum, Signature Series, Mark IV, Gen V/VI, 118cc chamber
12558162 01-P OVAL CLOSED Gen VII, Vortec 8100, 81L, 496, truck
12560241 98-P OVAL CLOSED Vortec 7400, 100cc chambers
12562932 91-95 OVAL OPEN Gen V, truck crate motor, 118cc chambers
12562933 91-95 OVAL OPEN Gen V, 118cc chambers
12562934 00-P RECT OPEN Gen VI, 502 Marine
14011077 69-P RECT OPEN Aluminum, Mark IV, C-port, 118cc chamber
14044861 84-96 RECT XXXX Bowtie, Aluminum, Mar IV, Gen V/VI , raised runner, 1st design, 105cc chamber, 2nd design 115cc chamber
14081045 78-87 OVAL OPEN 454
14081052 85-87 OVAL OPEN 366T, 427T, 454 Truck, Marked "HiPerf"
14092359 86-90 OVAL OPEN 366T, 427T, Marked "HiPerf"
14092360 86-90 OVAL OPEN 454 Truck, "peanut" round ports
14096188 70-71 RECT OPEN 454, Mark IV, 116cc chamber
14097088 91-P RECT OPEN Gen V 454/502 HO, 118cc chamber
24502585 GMPP RECT XXXX Olds/Chevy, DRCE 2, Pro Stock aluminum, for blocks w/ 4.900" bore spacing
25534404 GMPP RECT XXXX Olds/Chevy, DRCE 3, Pro Stock, aluminum, for blocks w/ 4.900" bore spacing
T=Tall deck block, Oval = Oval ports, large oval ports and peanut ports.