Pontiac heads have their casting codes cast on to the center exhaust ports. Together with the date code, you can determine the valve size and cc the chamber.
Casting #
|
Year
|
CID
|
HP
|
Valve
|
CC
|
Notes
|
518024
|
1955
|
287
|
173, 180, 200
|
1.78/1.50
|
||
522010
|
1956
|
316
|
192, 205, 216, 227, 285
|
1.78/1.50
|
||
523298
|
1957
|
347
|
227, 244, 252, 270, 290
|
1.78/1.50
|
||
524852
|
1957
|
347
|
317
|
1.78/1.50
|
Fuel Injection
|
|
528511
|
1958
|
347
|
310, 315, 330, 338
|
1.78/1.50
|
||
528511
|
1958
|
370
|
240, 255, 270, 285, 300
|
1.78/1.50
|
||
531395
|
1959
|
389
|
315, 330, 345
|
1.78/1.50
|
||
531395
|
1959
|
389
|
215, 245, 260, 280, 300
|
1.88/1.60
|
||
535461
|
1960
|
389
|
348, 363
|
1.92/1.60
|
68
|
Super Duty
|
536109
|
1960
|
389
|
303, 318, 333, 389, 348
|
1.88/1.60
|
||
536109
|
1960
|
389
|
215, 230, 235, 281, 283
|
1.88/1.60
|
||
538177
|
1961-62
|
389
|
1.88/1.60
|
|||
538177
|
1961-62
|
421
|
1.88/1.60
|
|||
540306
|
1961-62
|
389
|
368, 385
|
1.92/1.66
|
68
|
Super Duty
|
540306
|
1961-62
|
421
|
373, 405
|
1.92/1.66
|
68
|
Super Duty
|
544127
|
1961-62
|
421
|
373, 405
|
2.02/1.76
|
68
|
Super Duty
|
9771980
|
1962-63
|
421
|
390, 405, 410
|
2.02/1.76
|
68
|
Super Duty
|
543797
|
1963
|
326
|
250
|
1.88/1.60
|
||
543797
|
1963
|
389
|
267, 283, 303, 313
|
1.88/1.60
|
||
543797
|
1963
|
421
|
320
|
1.88/1.60
|
||
544127
|
1963
|
421
|
390, 405, 410
|
2.02/1.76
|
68
|
Super Duty
|
548332
|
1963
|
326
|
260, 280
|
1.92/1.66
|
68
|
|
9770716
|
1963
|
421
|
353, 370
|
1.92/1.66
|
68
|
HO
|
9772652
|
1963
|
326
|
260, 280
|
1.92/1.66
|
68
|
|
543796
|
1963-64
|
389
|
215, 230, 235
|
1.88/1.60
|
||
9770716
|
1964
|
389
|
325, 330, 348
|
1.92/1.66
|
68
|
GTO
|
9770716
|
1964
|
421
|
350, 370
|
1.92/1.66
|
68
|
|
9773345
|
1964
|
326
|
250
|
1.92/1.66
|
68
|
|
9773345
|
1964
|
389
|
267,283,303,306
|
1.92/1.66
|
68
|
|
9773345
|
1964
|
421
|
320
|
1.92/1.66
|
68
|
|
9773395
|
1964
|
326
|
280
|
1.92/1.66
|
68
|
|
22
|
1965
|
326
|
285
|
1.92/1.66
|
68
|
|
62
|
1965
|
326
|
250
|
1.92/1.66
|
68
|
|
75
|
1965
|
389
|
256
|
1.92/1.66
|
68
|
|
76
|
1965
|
389
|
290, 326, 333
|
1.92/1.66
|
68
|
GTO
|
76
|
1965
|
421
|
338
|
1.92/1.66
|
68
|
|
77
|
1965
|
389
|
335,338,360
|
1.92/1.66
|
68
|
|
77
|
1965
|
421
|
256, 376
|
1.92/1.66
|
68
|
HO
|
91
|
1966
|
389
|
256
|
1.92/1.66
|
68
|
|
92
|
1966
|
389
|
290, 325, 333
|
1.92/1.66
|
70
|
GTO
|
92
|
1966
|
421
|
338,350
|
1.92/1.66
|
70
|
|
93
|
1966
|
389
|
335,338,360
|
1.92/1.66
|
68
|
|
93
|
1966
|
421
|
256, 376
|
1.92/1.66
|
68
|
HO
|
94
|
1966
|
326
|
250
|
1.92/1.66
|
68
|
|
95
|
1966
|
326
|
285
|
1.92/1.66
|
68
|
|
97
|
1967
|
400
|
325,360
|
2.11/1.77
|
72
|
late Ram Air
|
61
|
1967
|
400
|
290 325, 333
|
2.11/1.77
|
72
|
|
140
|
1967
|
326
|
250
|
2.11/1.77
|
72
|
|
141
|
1967
|
326
|
285
|
2.11/1.77
|
72
|
|
142
|
1967
|
400
|
255, 260, 265
|
2.11/1.77
|
72
|
|
143
|
1967
|
400
|
290, 325, 333
|
2.11/1.77
|
72
|
|
187
|
1967
|
400
|
350
|
2.11/1.77
|
72
|
|
670
|
1967
|
400
|
325, 335, 360
|
2.11/1.77
|
72
|
RA
|
670
|
1967
|
428
|
360, 376
|
2.11/1.77
|
72
|
|
997
|
1967
|
400
|
325, 360
|
2.11/1.77
|
72
|
RA
|
671
|
1967
|
400
|
350
|
2:11/1.77
|
72
|
|
671
|
1967
|
428
|
360, 376
|
2.11/1.77
|
72
|
Early Grand Prix 428 H.O.
|
14
|
1968
|
400
|
265
|
2.11/1.77
|
72
|
|
15
|
1968
|
400
|
290, 340
|
2.11/1.77
|
72
|
|
16
|
1968
|
400
|
330, 335, 350, 360
|
2.11/1.77
|
72
|
HO
|
16
|
1968
|
428
|
375, 390
|
2.11/1.77
|
72
|
|
17
|
1968
|
350
|
265
|
2.11/1.77
|
||
18
|
1968
|
350
|
320
|
2.11/1.77
|
||
31
|
1968
|
400
|
335, 360
|
2.11/1.77
|
72
|
Ram Air
|
37
|
1968
|
400
|
335, 360
|
2.11/1.77
|
72
|
Ram Air
|
62
|
1968
|
400
|
330,335,350,360
|
2.11/1.77
|
72
|
AT
|
62
|
1968
|
428
|
375, 390
|
2.11/1.77
|
72
|
|
96
|
1968
|
400
|
340, 366
|
2.11/1.77
|
71
|
Ram Air II
|
214
|
1968
|
400
|
265
|
2.11/1.77
|
72
|
|
215
|
1968
|
400
|
290, 340
|
2.11/1.77
|
72
|
|
216
|
1968
|
400
|
330, 335.350,360
|
2.11/1.77
|
72
|
|
216
|
1968
|
428
|
375, 390
|
2.11/1.77
|
72
|
|
16
|
1969
|
400
|
330, 335, 340, 350, 366
|
2.11/1.77
|
72
|
Ram Air III
|
16
|
1969
|
428
|
360, 390
|
2.11/1.77
|
72
|
|
44
|
1969
|
400
|
375
|
2.19/1.66
|
Ram Air V
|
|
45
|
1969
|
400
|
265
|
2.11/1.77
|
||
46
|
1969
|
400
|
290
|
2.11/1.77
|
||
47
|
1969
|
350
|
265
|
2.11/1.77
|
||
48
|
1969
|
350
|
325
|
2.11/1.77
|
72
|
|
48
|
1969
|
400
|
330, 335, 350, 366
|
2.11/1.77
|
72
|
MT Ram Air III
|
62
|
1969
|
400
|
330, 335, 340, 350, 366
|
2.11/1.77
|
72
|
Ram Air III
|
62
|
1969
|
428
|
370, 390
|
2.11/1.77
|
72
|
|
722
|
1969
|
400
|
345, 370
|
2,11/1.77
|
71
|
Ram Air IV
|
184
|
1969
|
303
|
2.19/1.62
|
Ram Air V
|
||
722
|
1969
|
400
|
345, 370
|
2.11/1.77
|
71
|
Ram Air IV
|
11
|
1970
|
350
|
255
|
2.11/1.77
|
||
11
|
1970
|
400
|
265
|
2.11/1.77
|
||
12
|
1970
|
400
|
330, 350
|
2.11/1.77
|
72
|
MT Ram Air III
|
12
|
1970
|
400
|
345, 366
|
2.11/1.77
|
72
|
Ram Air III
|
13
|
1970
|
400
|
330, 350
|
2.11/1.77
|
72
|
AT Ram Air III
|
15
|
1970
|
455
|
360
|
2.11/1.77
|
72
|
|
16
|
1970
|
400
|
290, 330
|
2.11/1.77
|
Press-in studs
|
|
47
|
1970
|
350
|
255
|
2.11/1.77
|
||
47
|
1970
|
400
|
265
|
2.11/1.77
|
||
64
|
1970
|
455
|
360, 370
|
2.11/1.77
|
87
|
HO
|
614
|
1970
|
400
|
370
|
2,11/1,77
|
71
|
Ram Air IV
|
66
|
1971
|
455
|
325
|
2.11/1.77
|
114
|
AT
|
94
|
1971
|
350
|
250
|
2.11/1.77
|
96
|
|
96
|
1971
|
400
|
300
|
2.11/1.77
|
96
|
GTO
|
98
|
1971
|
455
|
280
|
2.11/1.77
|
111
|
|
99
|
1971
|
400
|
265
|
2.11/1.77
|
96
|
|
191
|
1971
|
455
|
335
|
2.11/1.77
|
111
|
HO
|
197
|
1971
|
455
|
335
|
2.11/1.77
|
111
|
HO
|
7F6
|
1972
|
455
|
300
|
2.11/1.77
|
111
|
HO
|
7H1
|
1972
|
350
|
175
|
2.11/1.77
|
96
|
|
7J2
|
1972
|
400
|
200
|
2.11/1.77
|
96
|
|
7K3
|
1972
|
400
|
250
|
2.11/1.77
|
96
|
|
7L4
|
1972
|
455
|
200
|
2.11/1.77
|
96
|
|
7M5
|
1972
|
455
|
250
|
2.11/1.77
|
111
|
|
16
|
1973
|
455
|
290
|
2.11/1.77
|
111
|
Super Duty, screw in studs
|
46
|
1973
|
350
|
150, 175
|
2.11/1.66
|
98
|
|
46
|
1973
|
400
|
170, 185
|
2.11/1.66
|
98
|
|
4C
|
1973
|
350
|
150, 175
|
2.11/1.66
|
98
|
|
4C
|
1973
|
400
|
170, 185, 200
|
2.11/1.66
|
98
|
|
4X
|
1973
|
400
|
200
|
2.11/1.66
|
98
|
|
4X
|
1973
|
400
|
230
|
2.11/1.66
|
98
|
screw in studs
|
4X
|
1973
|
455
|
215,250
|
2.11/1.66
|
114
|
screw in studs
|
16
|
1973
|
455
|
290
|
2.11/1.77
|
111
|
Super Duty , screw in studs
|
16
|
1974
|
455
|
290
|
2.11/1.77
|
111
|
Super Duty, screw in studs
|
46
|
1974
|
350
|
155, 170
|
2.11/1.66
|
98
|
|
46
|
1974
|
350
|
200
|
2.11/1.66
|
89
|
GTO screw in studs
|
46
|
1974
|
400
|
175, 190
|
2.11/1.66
|
98
|
|
4C
|
1974
|
350
|
155, 170
|
2.11/1.66
|
98
|
|
4C
|
1974
|
400
|
175, 190
|
2.11/1.66
|
98
|
|
4C
|
1974
|
400
|
200
|
2.11/1.66
|
98
|
|
4C
|
1974
|
400
|
225
|
2.11/1.66
|
98
|
AT, screw in studs
|
4X
|
1974
|
400
|
200
|
2.11/1.66
|
98
|
|
4X
|
1974
|
400
|
225
|
2.11/1.66
|
98
|
screw in studs
|
4X
|
1974
|
455
|
215, 250
|
2.11/1.66
|
114
|
screw in studs
|
51
|
1975
|
455
|
200
|
2.11/1.66
|
101
|
|
5C
|
1975
|
350
|
155, 175
|
2.11/1.66
|
101
|
|
5C
|
1975
|
400
|
185
|
2.11/1.66
|
101
|
|
6H
|
1975
|
455
|
200
|
2.11/1.66
|
124
|
HO
|
6S
|
1975
|
455
|
200
|
2.11/1.66
|
124
|
HO
|
6H
|
1976
|
455
|
200
|
2.11/1.66
|
124
|
|
6S
|
1976
|
350
|
160, 165
|
2.11/1.66
|
124
|
|
6S
|
1976
|
400
|
185
|
2.11/1.66
|
124
|
|
6X
|
1976
|
350
|
160, 165
|
2.11/1.66
|
101
|
|
6X
|
1976
|
400
|
185
|
2.11/1.66
|
101
|
|
01
|
1977
|
301
|
135
|
1.72/1.50
|
||
6S
|
1977
|
350
|
170
|
2.11/1.66
|
124
|
|
6X
|
1977
|
350
|
170
|
2.11/1.66
|
101
|
|
6X
|
1977
|
400
|
180, 200
|
2.11/1.66
|
101
|
|
01
|
1978
|
301
|
135
|
1.72/1.50
|
||
6X
|
1978
|
350
|
170
|
2.11/1.66
|
101
|
|
6X
|
1978
|
400
|
180, 220
|
2.11/1.66
|
101
|
|
01
|
1979
|
301
|
135
|
1.72/1.50
|
||
02
|
1979
|
301
|
150
|
1.72/1.50
|
||
6X
|
1979
|
400
|
220
|
2.11/1.66
|
101
|
Cylinder Heads
Year(s)
|
Engine
|
HP Rating
|
Head #
|
Valve Size
|
CC or CR
|
1959
|
389
|
215-345HP
|
531395
|
1.88/1.60
|
69
|
1960
|
389
|
215-345HP
|
536109
|
1.88/1.60
|
69
|
389SD
|
348-363HP
|
535461
|
1.92/1.60
|
69
|
|
1961
|
389
|
all
|
538177
|
1.88/1.60
|
69
|
421
|
all
|
538177
|
1.88/1.60
|
69
|
|
389SD
|
368/373HP
|
540306
|
1.92/1.66
|
68
|
|
421SD
|
368/373HP
|
540306
|
1.92/1.66
|
68
|
|
1962
|
389
|
all
|
538177
|
1.88/1.60
|
69
|
421
|
all
|
538177
|
1.88/1.60
|
69
|
|
389SD
|
385/405HP
|
540306/544127
|
1.92/1.66;2.02/1.76
|
68
|
|
421SD
|
385/405HP
|
540306/544127
|
1.92/1.66;2.02/1.76
|
68
|
|
1963
|
326
|
250HP
|
543797
|
1.88/1.60
|
8.6 c.r.
|
326
|
260/280HP
|
548232
|
1.88/1.60
|
10.25 c.r.
|
|
389
|
215/230/235HP
|
543796
|
1.88/1.60
|
8.6 c.r.
|
|
389
|
267/283/303/313HP
|
543797
|
1.88/1.60
|
10.25 c.r.
|
|
421
|
320HP
|
543797
|
1.88/1.60
|
10.75 c.r.
|
|
421
|
353/370HP
|
9770716
|
1.92/1.66
|
72
|
|
421SD
|
390/405/410HP
|
544127/9771980
|
2.02/1.76
|
64
|
|
1964
|
326
|
250HP
|
9773345 (845)
|
1.88/1.60
|
8.6 c.r.
|
326
|
280HP
|
9773395
|
1.88/1.60
|
10.0 c.r.
|
|
389
|
215/230/235HP
|
5437796
|
1.88/1.60
|
8.6
|
|
389
|
267/283/303/306HP
|
9773345/(845)
|
1.92/1.66
|
10.5 c.r.
|
|
421
|
320HP
|
9773345/(834)
|
1.92/1.66
|
10.75 c.r.
|
|
389
|
325/330/348HP
|
9770716
|
1.92/1.66
|
72
|
|
421
|
350/370HP
|
9770716
|
1.96/1.66
|
68
|
|
1965
|
326
|
250HP
|
62
|
1.88/1.60
|
8.6 c.r.
|
326
|
285HP
|
22
|
1.88/1.60
|
10.5 c.r.
|
|
389
|
256HP
|
75
|
1.88/1.60
|
8.6 c.r.
|
|
389
|
290/325/333HP
|
76
|
1.92/1.66
|
10.5 c.r.
|
|
389
|
335/338/360HP
|
77
|
1.92/1.60
|
10.5 c.r.
|
|
421
|
338HP
|
76
|
1.92/1.66
|
10.75 c.r.
|
|
421
|
356/376HP
|
77
|
1.92/1.60
|
10.75 c.r.
|
|
1966
|
326
|
250HP
|
094
|
1.88/1.60
|
8.6 c.r.
|
326
|
285HP
|
095
|
1.88/1.60
|
10.5 c.r.
|
|
389
|
256HP
|
091
|
1.92/1.66
|
8.6 c.r.
|
|
389
|
290/325/333HP
|
092
|
1.92/1.66
|
10.5 c.r.
|
|
389
|
335/360HP
|
093
|
1.92/1.66
|
10.5 c.r. 68cc
|
|
421
|
338/350HP
|
092
|
1.92/1.66
|
10.75 c.r. 70 cc
|
|
421
|
356/376HP
|
093
|
1.92/1.66
|
10.75 c.r. 68 cc
|
|
1967
|
326
|
250HP
|
140
|
1.92/1.64
|
9.2 c.r.
|
326
|
285HP
|
141
|
1.92/1.64
|
10.5 c.r.
|
|
400
|
255/260/265HP
|
142
|
1.92/1.64
|
8.6 c.r.
|
|
400
|
290HP
|
143
|
1.92/1.64
|
10.5 c.r.
|
|
400
|
290HP
|
061
|
2.11/1.77
|
10.5 c.r.
|
|
400
|
325/333HP Big Car
|
143
|
1.92/1.64
|
10.5 c.r.
|
|
400
|
325/333HP Big Car
|
061
|
2.11/1.77
|
10.5 c.r.
|
|
400
|
350HP(GP)
|
670/9787671/187
|
2.11/1.77
|
10.5 c.r. 72 cc
|
|
400
|
325/335/360HP
|
670
|
2.11/1.77
|
72 cc
|
|
400
|
325/360HP RA
|
670/97
|
2.11/1.77
|
72 cc
|
|
428
|
360/376HP
|
670/9787671
|
2.11/1.77
|
72 cc
|
|
1968
|
350
|
265HP
|
17
|
1.91/1.61
|
8.6 c.r.
|
350
|
320HP
|
18
|
1.91/1.61
|
10.5 c.r.
|
|
400
|
265HP
|
14
|
1.91/1.61
|
8.6 c.r.
|
|
400
|
290/340HP Big Car
|
15/215
|
1.91/1.61
|
10.5 c.r.
|
|
400
|
350HP (GP)
|
16/216/62
|
2.11/1.77
|
72-75 cc
|
|
400
|
330HP (FB)
|
16/216/62
|
2.11/1.77
|
72-75 cc
|
|
400
|
335/350/360HP
|
16/62
|
2.11/1.77
|
72-75 cc
|
|
400
|
335/360HP RA I
|
31/(37)
|
2.11/1.77
|
72 cc
|
|
400
|
340(FB)/366(GTO)
|
R/96/A(RA II)
|
2.11/1.77
|
72cc/rd port
|
|
428
|
375HP
|
16/216
|
2.11/1.77
|
72cc
|
|
428
|
390HP
|
16/216
|
2.11/1.77
|
72cc
|
|
1969
|
350
|
265HP
|
47
|
1.91/1.66
|
8.6 c.r.
|
350
|
325HP
|
48
|
2.11/1.77
|
10.5 c.r.
|
|
400
|
265HP
|
45
|
1.91/1.66
|
8.6 c.r.
|
|
400
|
290HP
|
46
|
1.91/1.66
|
10 c.r.
|
|
400
|
340HP(GP)
|
16/62
|
2.11/1.77
|
72 cc
|
|
400
|
330,335,350/366HP
|
16/62/48(MT)
|
2.11/1.77
|
72cc
|
|
400
|
345(FB)/370(GTO)
|
722(RA-IV)
|
2.11/1.77
|
71 cc
|
|
428
|
360HP
|
16(small-valve)46
|
1.91/1.66
|
10 c.r.
|
|
428
|
370HP (GP)
|
62
|
2.11/1.77
|
72 cc
|
|
428
|
390 HP
|
16/62
|
2.11/1.77
|
72 cc
|
|
400
|
375HP(RA-V)
|
44 Tunnel Port
|
2.11/1.77
|
67cc
|
|
303
|
RA=V Tunnel Port
|
546184
|
2.11/1.77
|
56cc
|
|
1970
|
350
|
255HP
|
11
|
1.94/1.66
|
8.8 c.r.
|
400
|
265HP
|
11
|
1.94/1.66
|
8.6 c.r.
|
|
400
|
290HP
|
16(sm valve)
|
1.94/1.66
|
10 c.r.
|
|
400
|
330HP Big Car
|
16
|
1.94/1.66
|
10 c.r.
|
|
400
|
330HP
|
12(m.t.)
|
2.11/1.77
|
72cc
|
|
400
|
330HP
|
13(a.t.)
|
2.11/1.77
|
72cc
|
|
400
|
345HP(FB/RAIII)
|
12
|
2.11/1.77
|
72cc
|
|
400
|
350HP(GP)
|
13
|
2.11/1.77
|
72cc
|
|
400
|
350HP(GTO)
|
12(MT)
|
2.11/1.77
|
72cc
|
|
400
|
350HP(GTO)
|
13(AT)
|
2.11/1.77
|
72cc
|
|
400
|
366HP(GTO)
|
12(RA III)
|
2.11/1.77
|
72cc
|
|
400
|
370HP(RA IV)
|
614(rd port)
|
2.11/1.77
|
71cc
|
|
455
|
360HP Big Car
|
15
|
1.96/1.66
|
87cc
|
|
455
|
360/370HP(GTO/GP)
|
64
|
2.11/1.77
|
87cc
|
|
1971
|
350
|
250HP
|
94
|
1.94/1.66
|
96cc
|
400
|
265HP
|
99
|
1.94/1.66
|
98cc
|
|
400
|
300HP
|
96
|
2.11/1.77
|
96cc
|
|
455
|
280HP
|
98
|
1.94/1.66
|
114cc
|
|
455
|
325HP
|
66
|
2.11/1.77
|
114cc
|
|
455
|
335HP (455HO)
|
197(191) rd port
|
2.11/1.77
|
111cc
|
|
1972
|
350
|
175HP
|
7h1
|
1.94/1.66
|
7.6cr
|
400
|
200HP
|
7j2
|
1.94/1.66
|
8.4cr
|
|
400
|
250HP
|
7k3
|
2.11/1.77
|
96cc
|
|
455
|
200HP
|
7L4
|
2.11/1.77
|
114cc
|
|
455
|
250HP
|
7M4
|
2.11/1.77
|
114cc
|
|
455
|
250HP
|
7M5
|
2.11/1.77
|
114cc
|
|
455
|
300HP(455HO)
|
7F6 rd port
|
2.11/1.77
|
111cc
|
|
1973
|
350
|
150/175HP
|
46/4c
|
1.96/1.66
|
96cc
|
400
|
170/185HP
|
46/4c
|
1.94/1.66
|
98cc
|
|
400
|
200HP
|
4x/4c
|
2.11/1.66
|
98cc
|
|
400
|
230HP
|
4x/screw-in stud
|
2.11/1.66
|
98cc
|
|
455
|
215/250HP
|
4x/screw-in stud
|
2.11/1.66
|
114cc
|
|
455
|
290HP(455SD)
|
16/X(rd port)
|
2.11/1.77
|
111cc
|
|
1974
|
350
|
155/170HP
|
46/4c
|
1.94/1.66
|
7.6cr
|
350
|
200HP(GTO)
|
46(screw-in studs)
|
2.11/1.66
|
7.6cr
|
|
400
|
175/190HP
|
46/4c
|
1.94/1.66
|
8.1cr
|
|
400
|
200HP
|
4x/4c
|
1.94/1.66
|
98cc
|
|
400
|
225HP(AT)
|
4x(screw-in stud)
|
2.11/1.66
|
98cc
|
|
400
|
225HP(AT)
|
4c
|
2.11/1.66
|
98cc
|
|
400
|
225HP(MT)
|
4x(screw-in stud)
|
2.11/1.66
|
98cc
|
|
455
|
215/250
|
4x(screw-in stud)
|
2.11/1.66
|
114cc
|
|
455
|
215/250
|
4c
|
2.11/1.66
|
114cc
|
|
455
|
290HP(455SD)
|
16/X(rd port)
|
2.11/1.77
|
111cc
|
|
1975
|
350
|
ALL
|
5c
|
2.11/1.66
|
7.6cr
|
350
|
Late
|
6X
|
2.11/1.66
|
7.6cr
|
|
400
|
ALL
|
5c/6s
|
2.11/1.66
|
7.6cr
|
|
400
|
Late
|
6X
|
2.11/1.66
|
7.6cr
|
|
455
|
AIR
|
6s
|
2.11/1.66
|
7.6cr
|
|
455
|
Early
|
51
|
2.11/1.66
|
7.6cr
|
|
455
|
Late
|
6X
|
2.11/1.66
|
7.6cr
|
|
455
|
All
|
5C
|
2.11/1.66
|
7.6cr
|
|
350
|
HO/non-air
|
6h
|
2.11/1.66
|
7.6cr
|
|
1976
|
350
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
400
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
|
455
|
AIR
|
6S
|
2.11/1.66
|
7.6cr
|
|
455
|
HO/non-air
|
6H
|
2.11/1.66
|
7.6cr
|
|
1977
|
301
|
ALL
|
01
|
1.72/1.50
|
8.2cr
|
350
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
|
400
|
180HP
|
6X
|
2.11/1.66
|
7.6cr
|
|
400
|
200HP
|
6X
|
2.11/1.66
|
8.0cr
|
|
1978
|
301
|
ALL
|
01/02
|
1.72/1.50
|
8.2cr
|
350
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
|
400
|
180HP
|
6X
|
2.11/1.66
|
7.6cr
|
|
400
|
220HP
|
6X
|
2.11/1.66
|
8.1cr
|
|
1979
|
301
|
ALL
|
01
|
1.72/1.50
|
8.2cr
|
400
|
ALL
|
6X
|
2.11/1.66
|
8.1cr
|
Pontiac Head Codes
1973/74 Stampings on Head codes - 4X, 46, 4C, 16/X
Stamped ID
|
Head # Code
|
MVMA Chamber Vol.
|
Valve Diameter
|
Valve Length
|
CID
|
1 / 1H
|
4X
|
112.30 cc's
|
2.11/1.66 valve
|
4.78"
|
455
|
2H
|
46
|
96.17 cc's
|
1.96/1.66 valve
|
4.86"
|
350
|
3 / 3H
|
4X
|
98.21 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
4 / 4H
|
4X
|
98.94 cc's
|
1.96/1.66 valve
|
4.86"
|
350/400
|
5H
|
4C (AIR)
|
96.17 cc's
|
1.96/1.66 valve
|
4.86"
|
350
|
6H
|
46
|
96.17 cc's
|
1.96/1.66 valve
|
4.86"
|
350
|
6H
|
16/X
|
110.74 cc's
|
2.11/1.77 valve
|
4.97"
|
455 SD
|
7 / 7H
|
4X
|
98.21 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
8 / 8H
|
4C (AIR)
|
98.94 cc's
|
1.96/1.66 valve
|
4.86"
|
400
|
*All rocker arms are threaded beginning with Motor Unit Number 709986 assembled on or about May 7, 1973.
|
|||||
1975 (early) Stampings on Head codes - 5C / 51 (5I)
Stamped ID
|
Head # Code
|
MVMA Chamber Vol.
|
Valve Diameter
|
Valve Length
|
CID
|
4
|
5C
|
93.74 cc's
|
2.11/1.66 valve
|
4.86"
|
350
|
6
|
5C / 51
|
124.51 cc's
|
2.11/1.66 valve
|
4.71"
|
455
|
7
|
5C (AIR)
|
100.04 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
8
|
5C
|
100.04 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
9
|
5C (AIR)
|
93.74 cc's
|
2.11/1.66 valve
|
4.86"
|
350
|
1975/79 Stampings on Head codes - 6X / 6H
Year
|
Stamped ID
|
Head # Code
|
MVMA Chamber Vol.
|
Valve Diameter
|
Valve Length
|
CID
|
1975-76
|
4
|
6X
|
93.74 cc's
|
2.11/1.66 valve
|
4.86"
|
350
|
6
|
6X
|
124.51 cc's
|
2.11/1.66 valve
|
4.71"
|
455
|
|
6
|
6H
|
124.51 cc's
|
2.11/1.66 valve
|
4.71"
|
455
|
|
7
|
6S (AIR)
|
100.04 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
|
8
|
6X
|
100.04 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
|
9
|
6S (AIR)
|
93.74 cc's
|
2.11/1.66 valve
|
4.86"
|
350
|
|
1977
|
4
|
6X
|
93.74 cc's
|
2.11/1.66 valve
|
4.86"
|
350 / 400 W72
|
8
|
6X
|
100.04 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
|
1978
|
8
|
6X
|
100.04 cc's
|
2.11/1.66 valve
|
4.86"
|
400
|
1978/79
|
4
|
6X
|
93.74 cc's
|
2.11/1.66 valve
|
4.86"
|
400 W72
|
Cylinder Heads
Year(s)
|
Engine
|
HP Rating
|
Head #
|
Valve Size
|
CC or CR
|
1955
|
287
|
192, 205, 216, 227 HP
|
518024
|
1.72 / 1.50
|
|
1956
|
317
|
192, 205, 216, 227 HP
|
522010
|
1.72 / 1.50
|
Standard head milled 0.072"
also provides 10:1 compression
(285 HP engine) per Factory Bulletin
|
317
|
285 HP (2x4V)
|
522845
|
1.72 / 1.50
|
||
1957
|
347
|
227,244,252,270,290 HP
|
523298
|
1.88 / 1.60
|
|
347
|
317 HP (F.I.)
|
52(4852)
|
1.88 / 1.60
|
Last 4 digits stamped on O.E. install
|
|
1958
|
370
|
528511
|
1.88 / 1.60
|
||
370
|
T395A
|
X528511O
|
1.88 / 1.60
|
||
370
|
F.I.
|
XX528511XX
|
1.88 / 1.60
|
||
1959
|
389
|
215-345HP
|
531395
|
1.88/1.60
|
69
|
1960
|
389
|
215-345HP
|
536109
|
1.88/1.60
|
69
|
389SD
|
348-363HP
|
535461
|
1.92/1.60
|
69
|
|
1961
|
389
|
all
|
538177
|
1.88/1.60
|
69
|
421
|
all
|
538177
|
1.88/1.60
|
69
|
|
389SD
|
368/373HP
|
540306
|
1.92/1.66
|
68
|
|
421SD
|
368/373HP
|
540306
|
1.92/1.66
|
68
|
|
1962
|
389
|
all
|
538177
|
1.88/1.60
|
69
|
421
|
all
|
538177
|
1.88/1.60
|
69
|
|
389SD
|
385/405HP
|
540306/544127
|
1.92/1.66;2.02/1.76
|
68
|
|
421SD
|
385/405HP
|
540306/544127
|
1.92/1.66;2.02/1.76
|
68
|
|
1963
|
326
|
250HP
|
543797
|
1.88/1.60
|
8.6 c.r.
|
326
|
260/280HP
|
548232
|
1.88/1.60
|
10.25 c.r.
|
|
389
|
215/230/235HP
|
543796
|
1.88/1.60
|
8.6 c.r.
|
|
389
|
267/283/303/313HP
|
543797
|
1.88/1.60
|
10.25 c.r.
|
|
421
|
320HP
|
543797
|
1.88/1.60
|
10.75 c.r.
|
|
421
|
353/370HP
|
9770716
|
1.92/1.66
|
72
|
|
421SD
|
390/405/410HP
|
544127/9771980
|
2.02/1.76
|
64
|
|
1964
|
326
|
250HP
|
9773345 (845)
|
1.88/1.60
|
8.6 c.r.
|
326
|
280HP
|
9773395
|
1.88/1.60
|
10.0 c.r.
|
|
389
|
215/230/235HP
|
5437796
|
1.88/1.60
|
8.6
|
|
389
|
267/283/303/306HP
|
9773345/(845)
|
1.88/1.60
|
10.5 c.r.
|
|
421
|
320HP
|
9773345/(834)
|
1.88/1.60
|
10.75 c.r.
|
|
389
|
325/330/348HP
|
9770716
|
1.92/1.66
|
72
|
|
421
|
350/370HP
|
9770716
|
1.92/1.66
|
68
|
|
1965
|
326
|
250HP
|
62 / 9780562
|
1.88/1.60
|
8.6 c.r.
|
326
|
285HP
|
22 / 9778922
|
1.88/1.60
|
10.5 c.r.
|
|
389
|
256HP
|
75 / 9778775
|
1.88/1.60
|
8.6 c.r.
|
|
389
|
290/325/333HP
|
76 / 9778776
|
1.92/1.66
|
10.5 c.r.
|
|
389
|
335/338/360HP
|
77 / 9778777
|
1.92/1.60
|
10.5 c.r.
|
|
421
|
338HP
|
76 / 9778776
|
1.92/1.66
|
10.75 c.r.
|
|
421
|
356/376HP
|
77 / 9778777
|
1.92/1.60
|
10.75 c.r.
|
|
1966
|
326
|
250HP
|
094
|
1.92/1.66
|
9.2 c.r.
|
326
|
285HP
|
095
|
1.92/1.66
|
10.5 c.r.
|
|
389
|
256HP
|
091
|
1.92/1.66
|
8.6 c.r.
|
|
389
|
290/325/333HP
|
092
|
1.92/1.66
|
10.5 c.r.
|
|
389
|
335/360HP
|
093
|
1.92/1.66
|
10.5 c.r. 68cc
|
|
421
|
338/350HP
|
092
|
1.92/1.66
|
10.75 c.r. 70 cc
|
|
421
|
356/376HP
|
093
|
1.92/1.66
|
10.75 c.r. 68 cc
|
|
1967
|
326
|
250HP
|
140
|
1.92/1.64
|
9.2 c.r.
|
326
|
285HP
|
141
|
1.92/1.64
|
10.5 c.r.
|
|
400
|
255/260/265HP
|
142
|
1.92/1.64
|
8.6 c.r.
|
|
400
|
290HP
|
143
|
1.92/1.64
|
10.5 c.r.
|
|
400
|
325/333HP Big Car
|
143
|
1.92/1.64
|
10.5 c.r.
|
|
400
|
350HP(GP)
|
670/9787671/187
|
2.11/1.77
|
10.5 c.r. 72 cc
|
|
400
|
290HP
|
061
|
2.11/1.77
|
10.5 c.r.
|
|
400
|
325/333HP Big Car
|
061
|
2.11/1.77
|
10.5 c.r.
|
|
400
|
325/335/360HP
|
670
|
2.11/1.77
|
72 cc
|
|
400
|
325/360HP RA
|
670/97
|
2.11/1.77
|
72 cc
|
|
428
|
360/376HP
|
670/9787671
|
2.11/1.77
|
72 cc
|
|
1968
|
350
|
265HP
|
17
|
1.96/1.66
|
9.2 c.r.
|
350
|
320HP
|
18
|
1.96/1.66
|
10.5 c.r.
|
|
400
|
265HP
|
14
|
1.96/1.66
|
8.6 c.r.
|
|
400
|
290/340HP Big Car
|
15/215
|
1.96/1.66
|
10.5 c.r.
|
|
400
|
350HP (GP)
|
16/216
|
2.11/1.77
|
72-75 cc
|
|
400
|
330HP (FB)
|
16/216
|
2.11/1.77
|
72-75 cc
|
|
400
|
335/350/360HP
|
16
|
2.11/1.77
|
72-75 cc
|
|
400
|
335/360HP RA I
|
31/(37)
|
2.11/1.77
|
72 cc
|
|
400
|
340(FB)/366(GTO)
|
R/96/A(RA II)
|
2.11/1.77
|
72cc/rd port
|
|
428
|
375HP
|
16/216
|
2.11/1.77
|
72cc
|
|
428
|
390HP
|
16/216
|
2.11/1.77
|
72cc
|
|
1969
|
350
|
265HP
|
47
|
1.96/1.66
|
8.6 c.r.
|
350
|
325HP
|
48
|
2.11/1.77
|
10.5 c.r.
|
|
400
|
265HP
|
45
|
1.96/1.66
|
8.6 c.r.
|
|
400
|
290HP
|
46
|
1.96/1.66
|
10 c.r.
|
|
400
|
340HP(GP)
|
62
|
2.11/1.77
|
72 cc
|
|
400
|
330,335,350/366HP
|
62/48(MT)
|
2.11/1.77
|
72cc
|
|
400
|
345(FB)/370(GTO)
|
722(RA-IV)
|
2.11/1.77
|
71 cc
|
|
428
|
360HP
|
46
|
1.96/1.66
|
10 c.r.
|
|
428
|
370HP (GP)
|
62
|
2.11/1.77
|
72 cc
|
|
428
|
390 HP
|
62
|
2.11/1.77
|
72 cc
|
|
400
|
375HP(RA-V)
|
44 Tunnel Port
|
2.11/1.77
|
67cc
|
|
303
|
RA=V Tunnel Port
|
546184
|
2.11/1.77
|
56cc
|
|
1970
|
350
|
255HP
|
11
|
1.96/1.66
|
8.8 c.r.
|
400
|
265HP
|
11
|
1.96/1.66
|
8.6 c.r.
|
|
400
|
290HP
|
16(sm valve)
|
1.96/1.66
|
10 c.r.
|
|
400
|
330HP Big Car
|
16
|
1.96/1.66
|
10 c.r.
|
|
400
|
330HP
|
12(m.t.)
|
2.11/1.77
|
72cc
|
|
400
|
330HP
|
13(a.t.)
|
2.11/1.77
|
72cc
|
|
400
|
345HP(FB/RAIII)
|
12
|
2.11/1.77
|
72cc
|
|
400
|
350HP(GP)
|
13
|
2.11/1.77
|
72cc
|
|
400
|
350HP(GTO)
|
12(MT)
|
2.11/1.77
|
72cc
|
|
400
|
350HP(GTO)
|
13(AT)
|
2.11/1.77
|
72cc
|
|
400
|
366HP(GTO)
|
12(RA III)
|
2.11/1.77
|
72cc
|
|
400
|
370HP(RA IV)
|
614(rd port)
|
2.11/1.77
|
71cc
|
|
455
|
360HP Big Car
|
15
|
1.96/1.66
|
87cc
|
|
455
|
360/370HP(GTO/GP)
|
64
|
2.11/1.77
|
87cc
|
|
1971
|
350
|
250HP
|
94
|
1.96/1.66
|
96cc
|
400
|
265HP
|
99
|
1.96/1.66
|
98cc
|
|
400
|
300HP
|
96
|
2.11/1.77
|
96cc
|
|
455
|
280HP
|
98
|
1.96/1.66
|
114cc
|
|
455
|
325HP
|
66
|
2.11/1.77
|
114cc
|
|
455
|
335HP (455HO)
|
197(191) rd port
|
2.11/1.77
|
111cc
|
|
1972
|
350
|
175HP
|
7h1
|
1.96/1.77
|
7.6cr
|
400
|
200HP
|
7j2
|
1.96/1.77
|
8.4cr
|
|
400
|
250HP
|
7k3
|
2.11/1.77
|
96cc
|
|
455
|
200HP
|
7L4
|
2.11/1.77
|
114cc
|
|
455
|
250HP
|
7M4
|
2.11/1.77
|
114cc
|
|
455
|
250HP
|
7M5
|
2.11/1.77
|
114cc
|
|
455
|
300HP(455HO)
|
7F6 rd port
|
2.11/1.77
|
111cc
|
|
1973
|
350
|
150/175HP
|
46/4c
|
1.96/1.66
|
96cc
|
400
|
170/185HP
|
46/4c
|
1.96/1.66
|
98cc
|
|
400
|
200HP
|
4x/4c
|
2.11/1.66
|
98cc
|
|
400
|
230HP
|
4x/screw-in stud
|
2.11/1.66
|
98cc
|
|
455
|
215/250HP
|
4x/screw-in stud
|
2.11/1.66
|
114cc
|
|
455
|
290HP(455SD)
|
16/X(rd port)
|
2.11/1.77
|
111cc
|
|
1974
|
350
|
155/170HP
|
46/4c
|
1.96/1.66
|
7.6cr
|
350
|
200HP(GTO)
|
46(screw-in studs)
|
1.96/1.66
|
7.6cr
|
|
400
|
175/190HP
|
46/4c
|
1.96/1.66
|
8.1cr
|
|
400
|
200HP
|
4x/4c
|
1.96/1.66
|
98cc
|
|
400
|
225HP(AT)
|
4x(screw-in stud)
|
2.11/1.66
|
98cc
|
|
400
|
225HP(AT)
|
4c
|
2.11/1.66
|
98cc
|
|
400
|
225HP(MT)
|
4x(screw-in stud)
|
2.11/1.66
|
98cc
|
|
455
|
215/250
|
4x(screw-in stud)
|
2.11/1.66
|
114cc
|
|
455
|
215/250
|
4c
|
2.11/1.66
|
114cc
|
|
455
|
290HP(455SD)
|
16/X(rd port)
|
2.11/1.77
|
111cc
|
|
1975
|
350
|
ALL
|
5c
|
2.11/1.66
|
7.6cr
|
400
|
ALL
|
5c/6s
|
2.11/1.66
|
7.6cr
|
|
455
|
AIR
|
6s
|
2.11/1.66
|
7.6cr
|
|
350
|
HO/non-air
|
6h
|
2.11/1.66
|
7.6cr
|
|
1976
|
350
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
400
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
|
455
|
AIR
|
6S
|
2.11/1.66
|
7.6cr
|
|
455
|
HO/non-air
|
6H
|
2.11/1.66
|
7.6cr
|
|
1977
|
301
|
ALL
|
01
|
1.72/1.50
|
8.2cr
|
350
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
|
400
|
180HP
|
6X
|
2.11/1.66
|
7.6cr
|
|
400
|
200HP
|
6X
|
2.11/1.66
|
8.0cr
|
|
1978
|
301
|
ALL
|
01/02
|
1.72/1.50
|
8.2cr
|
350
|
ALL
|
6X/6S
|
2.11/1.66
|
7.6cr
|
|
400
|
180HP
|
6X
|
2.11/1.66
|
7.6cr
|
|
400
|
220HP
|
6X
|
2.11/1.66
|
8.1cr
|
|
1979
|
301
|
ALL
|
01
|
1.72/1.50
|
8.2cr
|
400
|
ALL
|
6X
|
2.11/1.66
|
8.1cr
|
 - Copy.png){kind=small}