Pontiac Cylinder Head Codes
Wallace Racing
If you know the code number, try my new head search
Chart to mill Pontiac Cylinder Heads
Pontiac made closed chambered heads until 1967.
In 1967 Pontiac made some open chamber heads(i.e. 061).After 1967 the heads were open chamber heads.
Exhaust Crossover Port Matchings
With Head
And Manifold
Use Gasket
1965-71
1965-71
1965-71
1965-71
1972-79
1972-79
1972-79
1972-79
1972-79
1972-79
1965-71
1965-71**
** Use sheet stainless steel block off plate.
Head ID Location
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.
| 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
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
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
1.92/1.66
10.5 c.r.
421
338HP
76 / 9778776
1.92/1.66
10.75 c.r.
421
356/376HP
77 / 9778777
1.92/1.66
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
