Head Codes

Pontiac heads have their casting codes cast on to the center exhaust ports. Starting in 1965 they were a two or three digit code.

The date code is a 3 or 4 digit code. The first digit will be a letter.

A=January
B=February
C=March, etc.

Followed by a 1 or 2 digit number for the day of the month. The last digit will be the year. The date code is usually cast lust below the valve cover or under the valve cover.

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	389		1.88/1.60
538177	1961	421		1.88/1.60
540306	1961	389	368, 385	1.92/1.66	68	Super Duty
540306	1961	421	373, 405	1.92/1.66	68	Super Duty
544127	1961	421	373, 405	2.02/1.76	68	Super Duty
9771980	1962	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	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
1	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
1	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
1	1979	301	135	1.72/1.50
2	1979	301	150	1.72/1.50
6X	1979	400	220	2.11/1.66	101