Cylinder Head ID
Use these casting numbers to identify the heads you have.
Small Block Casting numbers
Casting Number
CID
Years
Valves
Comments
10065202
350
82-86
1.94/1.50
76cc
10065203
350
82-86
1.94/1.50
76cc
10065204
350
82-86
1.94/1.50
76cc
10065205
305
82-86
1.84/1.50
58cc
10065206
350
82-86
1.94/1.50
76cc
10065207
305
82-86
1.84/1.50
58cc
10088113
350
86-92
1.94/1.50
58cc Corvette Aluminum
10120928
350
87-94
1.94/1.50
76cc
10125320
350
94-96
2.00/1.55
Gen II LT1 cast iron version,
10128374
350
92-97
2.00/1.55
Gen II LT1 53 CC angle plug aluminum
10134363
Bowtie High Port 60 CC 210 ~ 258 CC
10159550
350
87-94
1.94/1.50
76cc
10159551
305
87-94
1.84/1.50
58cc
10159552
350
87-94
1.94/1.50
76cc
10159553
305
87-94
1.84/1.50
58cc
10185040
Splayed vavle head 45 CC angle plug
10205245
350
93
2.00/1.55
Gen II LT1 angle plug aluminum reverse flow cooling 175/68cc ports
10207643
350
94-97
2.00/1.55
Gen II LT1 angle plug aluminum reverse flow cooling 175/68cc ports
10208890
265
94-96
2.00/1.55
Gen II L99 4.3 Liter V-8, cast iron, reverse flow
10215339
346
97
2.00/1.55
Gen III LS1 aluminum 68cc
10239906
305/350
96-up
1.94/1.50
68cc Vortec
12367713
2.00/1.55
GM Fast burn 62 CC 210 CC intake runner angle plug Vortec
12480005
346
0
2.125/1.625
Gen III LS1 "GTZ" aluminum 38cc angle plug
12480011
SB2.2 head 48 ~ 54 CC angle plug 284 CC intake runner Bare heads.
12480034
2.02/1.60
Bowtie Phase III 64cc Angle plug 184 cc intake runner
12506450
350
87-94
1.94/1.50
76cc
12509859
305
87-94
1.84/1.50
58cc
12516852
350
87-94
1.94/1.50
76cc
12551561
350
96
2.00/1.55
Gen II LT1 angle plug aluminum reverse flow cooling
12552520
305
97-99
1.84/1.5
Vortec Truck L-35
12554290
350
94-96
2.00/1.55
Gen II LT1 cast iron version
12555690
350
96
2.00/1.55
Gen II LT-4 55 CC 195 CC intake runner Angle Plug
12555690
350
96
2.00/1.55
Gen II LT-4 55 CC 195 CC intake runner Angle Plug
12556743
325
99 & UP
2.00/1.55
Gen III 5.3L aluminum truck and van
12558059
305
97
1.84/1.5
L-35 Vortec truck
12558062
350
98
1.94/1.5
L-31 Vortec truck 64cc chambers 170cc intake port
12558062
305/350
96-up
1.94/1.50
68cc Vortec
12558806
346
97-98
2.00/1.55
Gen III LS1 aluminum 68cc
12559853
346
99 & UP
2.00/1.55
Gen III LS1 aluminum 68cc
12559895
325
00 & UP
2.00/1.55
Gen III 5.3L aluminum
12564241
346
00 & UP
2.00/1.55
Gen III LS1 aluminum 68cc
12564243
346
2
2.00/1.55
Gen III LS6 aluminum 68cc
12564243
346
2.00/1.55
Gen III LS-6 vette head 65 CC
14008856
267
79-81
1.71/1.50
14010201
305
82-85
1.84/1.50
58cc
14011034
350
80-up
2.02/1.60
64cc Bowtie
14011049
350
82-up
2.02/1.60
64cc Bowtie Aluminum
14014415
267/305
80-85
1.71/1.50
64cc Crack prone
14014416
267/305/350
80-86
1.84/1.50
64cc Crack prone
14019821
350
80-86
1.84/1.50
76cc
14019924
267
79-81
1.71/1.50
14019926
305
80-86
1.84/1.50
14020516
305/350
80-86
1.84/1.50
14020517
350
80-86
1.84/1.50
76cc
14020555
305
81
14020556
350
81
14022206
350
80
1.94/1.50
76cc
14022301
305
80-86
1.84/1.50
58cc
14022601
267/305
79-86
1.72/1.50 1.84/1.50
58cc
14022801
305
80-86
1.72/1.50
58cc
14034806
267
78-82
1.72/1.50
14034807
305
78-82
1.72/1.50
14034808
350
80-86
1.84/1.50
76cc
14034810
350
80-86
14034811
350
80-86
14039121
305
81-86
14039122
305
81-86
14071114
350
80-86
14075381
350
80-86
14079261
350
82-85
14085844
350
80-86
14089119
350
80-86
14096217
350
90-up
1.94/1.50
64cc Crate heads
14101081
305
87-94
1.84/1.50
58cc
14101083
350
88-94
1.94/1.50
64 cc
14102187
305
87-95
1.84/1.50
58cc
14102191
305/350
87-95
1.84/1.50
14102193
305/350
87-95
1.84/1.50
24502559
96-97
Bowtie SB2 1st design"mirror ports" aluminum
25534351C
2.00/1.55
Vortec Bowtie 65 CC 175 cc intake runner
25534371C
2.00/1.55
Vortec Bowtie 65 CC 206 cc intake runner
3238882
350
68-69
1.94/1.50
76cc
3297185
307/327/350
57-67
1.72/1.50
330545
350/400
71-75
2.02/1.60
76cc
330862
400
71-73
1.94/1.50
333881
350
71-76
2.02/1.60
76cc
333882
350/400
70-80
1.94/1.50
76cc
340292
350
73-80
2.02/1.60
64cc Angle plugs turbo' head No heat riser
354434
262/305
75-80
1.72/1.50
60cc
358741
262/305
71--79
1.72/1.50
359944
350
71-79
1.94/1.50
76cc
3636839
265
55
1.72/1.50
3703523
265
55
1.72/1.50
195HP
3713358
265
55-56
1.72/1.50
3713569
265
55-56
1.72/1.50
3725306
265
56
1.72/1.50
210HP Corvette
3731262
265
56
1.72/1.50
Dual Quad Corvette
3731539
283
57-66
1.72/1.50
283HP Corvette
3731544
265/283
55-61
1.72/1.50
Dual Quad Corvette
3731554
265/283
55-63
1.72/1.50
3731556
283
57
1.72/1.50
3731762
265
56
1.72/1.50
Dual Quad Corvette
3737775
283/327
62-67
1.72/1.50
3740997
283
57
1.72/1.50
Dual Quad FI & 4-brl 220-270HP
3743056
283
58
1.72/1.50
3743096
327
62-67
1.72/1.50
3747363
265
57-62
1.72/1.50
3748056
327
62-67
1.72/1.50
3748720
283
57-58
1.72/1.50
Dual Quad FI & 4-brl Corvette
3748770
283
55-62
1.72/1.50
Dual Quad FI & 4-brl Corvette
3748772
283
57-62
1.72/1.50
Dual Quad FI & 4-brl Corvette
3755537
283
57-62
1.72/1.50
3755538
283
59
1.72/1.50
250-290HP FI Corvette
3755539
283
58-62
1.72/1.50
3755549
283
57-62
1.72/1.50
3755550
283
57-62
1.72/1.50
Dual Quad FI & 4-brl Corvette
3755585
327
62-67
1.72/1.50
3755896
283
62-64
1.72/1.50
3760116
283
59
1.72/1.50
Dual Quad FI & 4-brl Corvette
376445
350
80-84
1.72/1.50
376450
262/305
75-76
1.72/1.50
376495
350
Jun-79
1.94/1.50
76cc
3767460
265/283/327
55-67
1.72/1.50
Car & Truck Corvette
3767462
327
62-67
1.72/1.50
3767465
283
60-61
1.72/1.50
Dual Quad FI & 4-brl Corvette
3767754
283
60-61
1.72/1.50
3767792
283
60-67
1.72/1.50
3770126
327/350
67-70
1.94/1.50
3773012
265
55
1.72/1.50
3774634
327
64-67
1.72/1.50
3774682
283/327
60-67
1.72/1.50
3774684
283/327
57-67
1.72/1.50
3774690
283
58
1.72/1.50
FI Corvette
3774692
283
58-64
1.72/1.50
Dual Quad FI & 4-brl Corvette
3782461
302/327/350
61-70
1.94/1.50
Dual Quad FI & 4-brl Corvette 2.02/1.60 Doubble humps 64cc
3782462
327
67
1.94/1.50
Corvette 2.02/1.60
3792563
327
65-67
3795896
283/307/327
58-72
1.72/1.50
60cc
3796896
283
64-67
1.72/1.50
60cc Chevy II
3798996
327
63-67
3814462
350
67
1.94/1.50
3814480
283/327
60-67
1.72/1.50
3814482
327
62-67
1.72/1.50
3817680
283
59
1.72/1.50
FI 4-brl
3817681
327
62-67
1.72/1.50
3817682
283
61-62
1.72/1.50
3836839
265
55
1.72/1.50
3836842
283/327
57-67
1.72/1.50
3836924
283
63-64
1.72/1.50
3836942
283
58-62
1.72/1.50
3837063
283
58-62
1.72/1.50
3837064
265/283
56-62
1.72/1.50
3837065
265
55-56
1.72/1.50
3837775
283/327
62-67
1.72/1.50
383882
400
71-73
3848720
283
57-58
1.72/1.50
3849820
327
65
1.72/1.50
3854520
283/327
62-67
1.72/1.50
3867802
283
57-60
1.72/1.50
FI Corvette
3873064
265
56-57
1.72/1.50
3876487
350
71-73
1.94/1.50
76cc
3876775
283/327
57-67
1.72/1.50
76cc
3878775
327
64-67
1.72/1.50
3884520
283/327
60-67
1.72/1.50
60cc
3890462
302/327/350
62-68
1.94/1.50 2.02/1.60
64cc Doubble humps
3891462
302/327/350
62-67
1.94/1.50 2.02/1.60
64cc
3891492
327
64-67
1.94/1.50
3911011
327
68
3911032
307/327
68-70
1.72/1.50
70cc
3912264
283
58-62
1.72/1.50
3912265
283
63-64
1.72/1.50
3912291
302/327/350
68-70
1.94/1.50 2.02/1.60
64ccDoubble humps
3912311
350
67
1.94/1.50
3912313
327
65-73
1.72/1.50
3917264
302
67
2.02/1.60
64cc Z-28
3917290
327
68-70
1.72/1.50
3917291
302/327/350
62-69
1.94/1.50 2.02/1.60
64cc Doubble humps
3917292
327
67-68
1.94/1.50
3917293
307/327
68-69
1.72/1.50
76cc
3921175
327
66
1.94/1.50
3923441
350
67-76
1.94/1.50
76cc
3927185
307/327/350
68-79
1.72/1.50
70cc
3927186
302/327/350
68-72
1.94/1.50 2.02/1.60
64cc Doubble humps Bolt holes
3927187
302/350
69-70
2.02/1.60
64cc Corvette
3927188
307/327/350
69
1.72/1.50
76cc
3928454
307
68
1.72/1.50
3928455
302/327
68
2.02/1.60
64cc 325 & 350HP
3928494
327
68
2.02/1.60
64cc 350HP 4-brl
3928495
327
68
1.72/1.50
3931633
307
68-73
1.72/1.50
3931635
350
68-76
1.94/1.50
76cc
3931637
327
68-69
3931638
327
68
1.72/1.50
3931639
302
68
2.02/1.60
64cc
3932441
327/350
67-79
1.94/1.50
76cc
3932454
307/350
68-799
1.72/1.50
76cc
3933148
350
68-73
76cc
3941174
327
68
1.72/1.50
3946812
350
69
1.72/1.50
3946813
350
69-79
76cc
3947014
350
68-70
3947040
302/327/350
68-70
1.94/1.50 2.02/1.60
64cc
3947041
302/327/350
68-79
1.94/1.50 2.02/1.60
64cc
3951598
400
70-71
1.94/1.50
76cc
3961598
400
70-76
1.94/1.50
76cc
3964286
350
68-77
1.94/1.50
76cc
3970126
327/350
67-79
1.72/1.50
3973195
400
71-73
1.94/1.50
76cc
3973414
327/350
64-70
2.02/1.60
64cc Z-28 LT-1 corvette
3973487
350
68-79
1.94/1.50 2.02/1.60
76cc
3973487X
350
68-73
1.94/1.50 2.02/1.60
76cc X cast 10cc's
3973493
400
70-76
1.94/1.50
76cc
3986316
350
71-72
2.02/1.60
76cc
3986330
350
69-79
1.94/1.50
76cc
3986339
307/350
68-79
1.72/1.50
76cc
3986388
350
68-79
1.72/1.50
76cc
3990941
307/350
68-82
3991492
327/350
68-73
1.94/1.50 2.02/1.60
64cc Angle plug
399380
400
70-73
76cc
3997417
307
71
1.72/1.50
3998916
350/400
72-75
2.02/1.60
76cc
3998920
350
72-75
1.94/1.50
76cc
3998991
307/350
68-79
1.72/1.50
76cc
3998993
307/350
68-79
1.71/1.50 1.94/1.50
76cc
3998997
350/400
71-73
1.94/1.50
76cc
426424
305/350/400
72-82
1.72/1.50
458624
350
69-84
1.94/1.50
76cc
460703
350
78-80
1.94/1.50
76cc
462614
305/350
77-79
1.72/1.50
462624
350
76-87
1.94/1.50 2.02/1.60
76cc Crack prone
464033
350
76-86
1.94/1.50
76cc
464036
350
76-86
1.94/1.50
76cc
468642
350/400
75-84
1.72/1.50
471513
267
79-81
1.72/1.50
472424
305
76-79
1.72/1.50
474213
305
78-82
1.72/1.50
474214
350
78-82
1.94/1.50
76cc
475590
400
78-82
1.94/1.50
76cc
517513
267
79-81
1.72/1.50
6259515
350
73
6260855
350
73-75
1.94/1.50
76cc
6260856
350
73-76
1.94/1.50
76cc
6272070
350
73
10045427
Pontiac/Chevy Aluminum, 91cc chamber Large Rectangle Port
10049875
Pontiac/Chevy Aluminum Small Rectangle port
10051128
454
90-94
2.19/1.88
72cc Bowtie Aluminum Rectangular port 400cc intake
10052902
427
Oval Port Open chamber
10101136
454
91-94
2.06/1.77
Open chamber Oval port
10101140
366/427
91-01
Oval Port Closed chamber
10114156
454
91-01
Oval Port Open chamber
10121033
454
78-88
2.06/1.77
Open chamber Oval port
10141279
454
96-01
Vortec 7400 100cc chambers Oval Port
10487052
366
77-90
Oval Port Open chamber
12352783
454
79-93
2.06/1.77
Open chamber Oval port
12363391
Oval Port Bowtie Aluminum Signature Series
12363401
Rectangle Port Bowtie Aluminum Signature Series
12558162
496
01 & UP
Gen.VII Vortec 8100 8.1L truck
12560241
454
98-01
Vortec 7400 100cc chambers Oval Port
12562932
454/502
91-95
Oval Port truck crate motor 118cc chambers
12562934
502
00 & UP
GenVI Marine
14011077
454
89-94
2.19/1.88
118cc Replacement Aluminum Rectangular port 295cc intake
14025175
454
83-93
2.06/1.77
Open chamber Oval port
14044861
454
89-94
2.19/1.88
106cc Bowtie Aluminum Rectangular port 380cc intake
14081044
454
86-90
2.06/1.77
Open chamber Oval port
14081045
454
78-87
Oval Port Open chamber
14081052
366/427/454
85-87
Oval Port Open chamber
14092359
427
86-89
2.06/1.77
Open chamber Oval port
14092360
454
85-89
2.06/1.77
Open chamber Oval port
14096188
454
87-94
2.19/1.88
118cc Replacement Rectangular port 325cc intake
14097088
502
89-date
2.19/1.88
118cc Replacement Rectangular port 325cc intake GEN V
14101398
454
86-90
2.06/1.77
Open chamber Oval port
24502585
Olds/Chevy DRCE 2 Pro Stock aluminum
330864
366/427/454
70-81
2.06/1.77
Open chamber Oval port
330865
366/427/454
70-84
2.06/1.77
Open chamber Oval port
330866
366/427
68-78
Oval Port Open chamber
330867
427
68-73
Oval Port Open chamber
336768
427
73-76
Oval Port Open chamber
336781
454
73-85
2.06/1.77
113cc Oval port
343771
366/427/454
68-85
2.06/1.77
Open chamber Oval port
343772
366/427/454
76-84
2.06/1.77
Open chamber Oval port
343783
454
75-78
2.06/1.77
Open chamber Oval port
346236
454
75-87
2.06/1.77
113cc Oval port
346238
454
75-87
2.06/1.77
113cc Oval port
352625
454
70-76
Oval Port Open chamber
353049
454
70-73
2.06/1.77
113cc Oval port
366765
427/454
73-84
2.06/1.77
Open chamber Oval port
3732791
348
58
3758379
348
59-61
3759256
348
58
3767738
348
59-61
3781147
348
60-61
High Perf
3795586
409
61
360HP
3814690
409
62-64
High Perf
3819333
348/409
62-65
3830817
409
63-65
340HP
3837731
409
63
High Perf Z-11
3852583
409
65
400HP
3856206
396
65-66
2.06/1.77
98cc Oval port
3856208
396
65
2.06/1.77
109cc Z-16/L-37 Rectangular port
3856213
366
66-70
2.06/1.77
Closed chamber Oval port
3856260
396
68
Oval Port Closed chamber
3872702
396/427
66
2.06/1.77
98cc Oval port L-34/L-35/L-36
3873858
396/427
66-67
2.06/1.77
109cc L-78/L-72 Rectangular port
3876875
427
66-70
2.06/1.77
Closed chamber Oval port
3904390
396/427
66-67
2.06/1.77
98cc Oval port L-34/L-35/L-36
3904391
396/427
65-67
2.06/1.77
107cc L-78/L-71/L-72 Rectangular port
3904392
427
67
2.19/1.88
106cc L-88/L-89 Aluminum Rectangular port
3904393
366
66-68
2.06/1.77
Closed chamber Oval port
3908952
427
67
Oval Port Open chamber
3909802
396/427
66-67
2.06/1.77
100cc Oval port L-34/L-35/L-36/L-68
3917215
396/427
67-69
2.06/1.77
100cc Oval port L-34/L-35
3917219
366/427
66-70
2.06/1.77
Closed chamber Oval port
3919840
396/427
67-69
2.06/1.77
107cc L-78/L-71/L-72 Rectangular port
3919842
396/427
68-69
2.19/1.88
106cc L-88/L-89 Aluminum Rectangular port
3931063
396/427
69-70
2.06/1.77
100cc Oval port L-34/L-35
3933148
366/396/427
69
2.06/1.77
122cc Oval port
3933149
427
69-70
2.06/1.77
122cc Oval port
3935401
427
68-76
Oval Port Open chamber
3946074
396/454
69-71
2.19/1.88
118cc L-88/ZL-1 Aluminum Rectangular port
3964280
427/454
66-70
2.06/1.77
Closed chamber Oval port
3964290
396/402/427/454
69-70
2.06/1.77
100cc Oval port
3964291
396/402/427/454
69-70
2.19/1.88
108cc L-78/L-71/L-72/LS-6 Rectangular port 325cc intake
3964292
454
70
2.19/1.88
109cc LS-6 Rectangular port
3965198
396
69
2.06/1.77
Open chamber Oval port
3975950
366/427
68-70
2.06/1.77
Closed chamber Oval port
3986133
366/427
70-85
2.06/1.77
Closed chamber Oval port
3986136
366/427
70-84
2.06/1.77
Closed chamber Oval port
3993820
402/454
71
2.06/1.77
113cc Oval port
3994025
454
71
2.19/1.88
118cc LS-6 Rectangular port
3994026
454
71
2.19/1.88
118cc LS-6 Rectangular port
3999241
402/454
72
2.06/1.77
113cc Oval port
473328
366
68-85
2.06/1.77
Open chamber Oval port
6258723
454
71
2.19/1.88
118cc LS-6 Rectangular port
6272292
402/454
71
2.06/1.77
Open chamber Oval port
6272990
454
71-94
2.19/1.88
118cc Replacement Rectangular port 325cc intake