Pontiac V8 Cylinder Heads

Compression can be increased or deceased through proper cylinder head selection. It's important to know how to identify Pontiac heads in order to pick the right one for your engine. There are d-port heads and round port heads. That characteristic difference is apparent by looking at the exhaust port openings. Most Pontiac heads are d-ports. Very few are round ports and those are automatically considered performance heads. The round port heads were highly desired for performance builds, but now most performance build go with the Edelbrock heads. The round port heads are mostly hunted by those doing correct restorations.

Another thing to look at when examining a head is to see if the head has push in studs, or is equipped with screw in studs. Generally, Pontiac heads that are considered high performance by PMD (and by enthusiasts) will have screw in studs and push rod guide plates. Some d-port heads will have screw in studs. Some do not. Any d-port head having pressed in studs may be modified to accept screw in studs. Any quality machine shop can perform this job. Most importantly, all d-port heads can be ported to provide increased air flow. Air flow is one of the keys to making more power in any combustion engine.

What else to look for? Every Pontiac head has a casting identifier on the head. Some have a long string of numbers, some have 2 or 3 numbers, and yet others (low compression, large chambered from the '70s) are alphanumeric...a number or two and a letter cast into the head. With few exceptions, most casting identifiers are on the two center exhaust ports. However, many of these seem to be missing, likely due to age and rust. Especially on heads between 1966 and 1970. The heads from the '70s through '79 still seem to be found in pretty good shape. Most of those are alphanumeric.

A casting date is also important to locate. The head casting date is usually found on the exhaust side of the head just below the valve cover rail. If you must, scrape away some of the grime to find the information. A letter is usually followed by three numbers. The letter stands for the month. A=January, B=February and so on. Keep in mind that the month of the year may fall into the next year's production. The numbers that follow the letter is the day of the month. The last number is the calendar year.

For example: A109 is probably a casing from January 10, 1969; a head casting with E248 is a casting from 1968 or 1978. If the casting identifier on the center exhaust ports is visible and it's alphanumeric (E.g. 6x) then it's from 1978. If there are two numbers, say 16, or 62 or 48, it's a 1968 casting. The casting date and the casting identifier are critical to identifying a Pontiac head.

In the example below, the cylinder head has a casting date of K134, and an ID code of 4C. K = November, 13 is the 13th day, and 4 would be either 1964, or 1974. The ID code is 4C. Looking at the chart below, we can see that this is a 1974 Pontiac 400/455 head.

One other thing...never rely on the purported chamber size of any Pontiac head. Too much time has passed. Many heads have been milled and the chamber size altered. The best way to know chamber size is to measure their volume (CC the heads).

Interchanging Cylinder 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.

Pontiac Intake Manifold Years Interchange

1957-1958

1959-1960

1961-1964

1965-1979

Does not apply to 301 or the RA V

Pontiac Intake Manifold Interchanges:

Pontiac Intake Manifold Years Interchange

1957-1958

1959-1960

1961-1964

1965-1979

Does not apply to 301 or the RA V

Cylinder Head Chart (table):

Have a cylinder head casting number, and don't know what it's from? Use the table below.

You can search the table by:

Head Casting Number, Year, Engine, Stud Mount Type, or any other variable shown in the table.

Search:   Cancel Search

Head Casting NumberYearEngineRated HorsepowerValve Size (Intake / Exhaust)Chamber Volume (or Compression Ratio if Volume Unknown)Stud Mounts
011977301ALL1.72 / 1.508.2:1 CRScrew
011978301ALL1.72 / 1.508.2:1 CRScrew
011979301ALL1.72 / 1.508.2:1 CRScrew
011980301ALL1.72 / 1.50 Screw
011981301ALL1.72 / 1.50Screw
021978301ALL1.72 / 1.508.2:1 CRScrew
111970350255 hp1.94 / 1.668.8:1 CRPressed
111970400265 hp1.94 / 1.6680 ccPressed
121970400 Ram Air III345 hp (Firebird)2.11 / 1.7772 ccScrew
121970400 Ram Air III366 hp (GTO)2.11 / 1.7772 ccPressed
12 (Manual Trans)1970400 Ram Air III330 hp2.11 / 1.7772 ccScrew
12 (Manual Trans)1970400350 hp (GTO)2.11 / 1.7772 ccPressed
131970400350 hp (Grand Prix)2.11 / 1.7772 ccScrew
13 (Auto Trans)1970400330HP2.11 / 1.7772 ccScrew
13 (Auto Trans)1970400350 hp (GTO)2.11 / 1.7772 ccPressed
141968400265 hp1.96 / 1.6690 ccPressed
151968400290, 340 hp (FullSize)1.96 / 1.6675 ccPressed
151970455360 hp (FullSize)1.96 / 1.6687 ccPressed
161968400350 hp (Grand Prix)2.11 / 1.7772-75 ccScrew
161968400330 hp (Firebird)2.11 / 1.7772-75 ccScrew
161968400335, 350, 360 hp2.11 / 1.7772-75 ccScrew
161968428375 hp2.11 / 1.7772 ccScrew
161968428390 hp2.11 / 1.7772 ccScrew
161969400340 hp2.11 / 1.7772 ccScrew
161969400 Ram Air III330,335,350,366 hp2.11 / 1.7772 ccScrew
161969428390 hp2.11 / 1.7772 ccScrew
161970400330 hp (FullSize)1.94 / 1.6678 ccPressed
161973455 SD290 hp2.11 / 1.77111 ccScrew
161974455 SD290 hp2.11 / 1.77111 ccScrew
16 (small valve)1969428360 hp1.91/1.6610:1 CRScrew
16 (small valve)1970400290 hp1.94 / 1.6678 ccPressed
171968350265 hp1.96 / 1.6672 ccPressed
181968350 HO320 hp1.96 / 1.6664 ccPressed
221965326285 hp1.88 / 1.6060 ccPressed
311968400 Ram Air I335, 360 hp2.11 / 1.7772 ccScrew
371968400 Ram Air I335, 360 hp2.11 / 1.7772 ccScrew
44 (Tunnel Port)1969400 Ram Air V375HP (RA V)2.11 / 1.7767 ccScrew
451969400265 hp1.91 / 1.6694 ccPressed
461969400290 hp1.91 / 1.6668 ccPressed
461969428360 hp1.91/1.6610:1 CRScrew
461973350150, 175 hp1.94 / 1.6696 ccPressed
461974350155, 170 hp1.94 / 1.6698 ccScrew
461974350200 hp (GTO)2.11 / 1.6689 ccScrew
471969350265 hp1.91 / 1.6672 ccPressed
481969350 HO325 hp2.11 / 1.7764 ccPressed
481969400 Ram Air III330,335,350,366 hp2.11 / 1.7772 ccScrew
511975455AIR2.11 / 1.66124 ccScrew
611967400290 hp2.11 / 1.7772 ccPressed
611967400325, 333 hp (FullSize)2.11 / 1.7772 ccPressed
621965326250 hp1.88 / 1.6070 ccPressed
621968400350 hp (Grand Prix)2.11 / 1.7772-75 ccScrew
621968400330 hp (Firebird)2.11 / 1.7772-75 ccScrew
621968400335, 350, 360 hp2.11 / 1.7772-75 ccScrew
621969400340 hp2.11 / 1.7772 ccScrew
621969400 Ram Air III330,335,350,366 hp2.11 / 1.7772 ccScrew
621969428370 hp2.11 / 1.7772 ccScrew
621969428390 hp2.11 / 1.7772 ccScrew
641970455360, 370 hp (GTO, Grand Prix)2.11 / 1.7787 ccScrew
661971455325 hp2.11 / 1.77114 ccScrew
751965389256 hp1.88 / 1.6092 ccPressed
761965389290, 325, 333 hp1.92 / 1.6670 ccPressed
761965421338 hp1.92 / 1.6668 ccPressed
771965389335, 338, 360 hp1.92 / 1.6670 ccPressed
771965421356, 376 hp1.92 / 1.6668 ccPressed
911966389256 hp1.92 / 1.6692 ccPressed
921966389290, 325, 333 hp1.92 / 1.6610.5:1 CRScrew
921966421338, 350 hp1.92 / 1.6670 ccScrew
0931966389335, 360 hp1.92 / 1.6668 ccScrew
0931966421 HO356, 376 hp1.92 / 1.6668 ccScrew
941966326250 hp1.88 / 1.6068 ccPressed
941971350250 hp1.94 / 1.6696 ccPressed
951966326285 hp1.88 / 1.6010.5:1 CRPressed
96 (Round Port)1968400 Ram Air II340 hp (Firebird), 366 hp (GTO)2.11 / 1.7771 ccScrew
96 (Round Port)1971400300 hp2.11 / 1.7796 ccScrew
971967400 (Ram Air)325, 360 hp2.11 / 1.7772 ccScrew
981971455280 hp1.94 / 1.66114 ccPressed
991971400265 hp1.94 / 1.6698 ccPressed
1401967326250 hp1.92 / 1.669.2:1 CRPressed
1411967326285 hp1.92 / 1.6610.5:1 CRPressed
1421967400255, 260, 265 hp1.92 / 1.6690 ccPressed
1431967400290 hp1.92 / 1.6675 ccPressed
1431967400325, 333 hp (FullSize)1.92 / 1.6675 ccPressed
191 (Round Port)1971455 HO335 hp2.11 / 1.77111 ccScrew
1971968400290, 340 hp (FullSize)1.96 / 1.6675 ccPressed
2151968400350 hp (Grand Prix)2.11 / 1.7772-75 ccScrew
2161968400330 hp (Firebird)2.11 / 1.7772-75 ccScrew
2161968428375 hp2.11 / 1.7772 ccScrew
2161968428390 hp2.11 / 1.7772 ccScrew
2161967400350 hp2.11 / 1.7772 ccPressed
614 (Round Port)1970400 Ram Air IV370 hp2.11 / 1.7771 ccScrew
6701967400325, 335, 360 hp2.11 / 1.7772 ccScrew
6701967400 (Ram Air)325, 360 hp2.11 / 1.7772 ccScrew
6701967428360, 376 hp2.11 / 1.7772 ccScrew
6701964421320 hp1.92 / 1.6670 ccPressed
8341964326250 hp1.88 / 1.6070 ccPressed
8451964389267, 283, 303, 306 hp1.92 / 1.6670 ccPressed
8451960389 SD 1.92 / 1.66 Pinned
5354611961389ALL1.88 / 1.6069 ccPressed
5381771961421ALL1.88 / 1.6069 ccPressed
5381771962389ALL1.88 / 1.6069 ccPressed
5381771962421ALL1.88 / 1.6069 ccPressed
5381771959389368-373 hp1.88 / 1.6069 ccPressed
5403061959421368-373 hp1.88 / 1.6069 ccPressed
5403061960389368-373 hp1.88 / 1.6069 ccPressed
5403061960421368-373 hp1.88 / 1.6069 ccPressed
5403061961389 SD368, 373 hp1.92 / 1.6669 ccPinned
5403061961421 SD368, 373 hp1.92 / 1.6669 ccPinned
5403061962389 SD368, 373 hp1.92 / 1.6669 ccPinned
5403061962421 SD368, 373 hp1.92 / 1.6669 ccPinned
5403061961389 SD385, 405 hp2.02 / 1.7667 ccPinned
5403061961421 SD385, 405 hp2.02 / 1.7667 ccPinned
5403061962389 SD385, 405 hp2.02 / 1.7667 ccPinned
5403061962421 SD385, 405 hp2.02 / 1.7667 ccPinned
5403061963389215, 230, 235 hp1.88 / 1.6092 ccPressed
5437961963326250 hp1.88 / 1.6072 ccPressed
5437971963389267, 283, 303, 313hp1.88 / 1.6072 ccPressed
5437971963421320 hp1.88 / 1.6072 ccPressed
5437971961389 SD385, 405 hp2.02 / 1.7667 ccPinned
5441271961421 SD385, 405 hp2.02 / 1.7667 ccPinned
5441271962389 SD385, 405 hp2.02 / 1.7667 ccPinned
5441271962421 SD385, 405 hp2.02 / 1.7667 ccPinned
5441271963421 SD390, 405, 410 hp2.02 / 1.7664 ccPressed
5441271963326260, 280 hp1.88 / 1.6010.25:1 CRPressed
5482321964389215, 230, 235 hp1.88 / 1.6092 ccPressed
54377961963421 HO353, 370 hp1.92 / 1.6672 ccPressed
97707161964389325, 330, 348 hp1.96 / 1.6672 ccPressed
97707161964421 HO350, 370 hp1.96 / 1.6672 ccPressed
97707161963421 SD390, 405, 410 hp2.02 / 1.7664 ccPressed
97719801964326250 hp1.88 / 1.6070 ccPressed
97733451964389267, 283, 303, 306 hp1.92 / 1.6670 ccPressed
97733451964421320 hp1.92 / 1.6670 ccPressed
97733451964326280 hp1.88 / 1.6010:1 CRPressed
97733451967400350 hp2.11 / 1.7772 ccPressed
97876711967428360, 376 hp2.11 / 1.7772 ccScrew
97876711971455 HO335 hp2.11 / 1.77111 ccScrew
4C1973350150, 175 hp1.94 / 1.6696 ccPressed
4C1973400170, 185 hp1.94 / 1.6698 ccPressed
4C1973400200 hp2.11 / 1.6698 ccPressed
4C1974350155, 170 hp1.94 / 1.6698 ccScrew
4C1974400175, 190 hp1.94 / 1.6689 ccScrew
4C1974400200HP1.94 / 1.6698 ccScrew
4C1974400225 hp (Auto Trans)2.11 / 1.6698 ccScrew
4C1974455215, 2502.11 / 1.66114 ccScrew
4X1973400200 hp2.11 / 1.6698 ccPressed
4X1973400230 hp2.11 / 1.6698 ccScrew
4X1973455215, 250 hp2.11 / 1.66114 ccScrew
4X1974400200HP1.94 / 1.6698 ccScrew
4X1974400225 hp (Auto Trans)2.11 / 1.6698 ccScrew
4X1974400225 hp (Manual Trans)2.11 / 1.6698 ccScrew
4X1974455215, 2502.11 / 1.66114 ccScrew
5C1975350ALL2.11 / 1.66101 ccScrew
5C1975400ALL2.11 / 1.6698 ccScrew
6H1975455 HONon-Air2.11 / 1.66124 ccScrew
6H1976455 HONon-Air2.11 / 1.66124 ccScrew
6S1975400ALL2.11 / 1.6698 ccScrew
6S1975455AIR2.11 / 1.66115 ccScrew
6S1976350ALL2.11 / 1.6694 ccScrew
6S1976400ALL2.11 / 1.66101 ccScrew
6S1976455AIR2.11 / 1.66115 ccScrew
6S1977350ALL2.11 / 1.6694 ccScrew
6S1978350ALL2.11 / 1.667.6:1 CRScrew
6X1975455Late2.11 / 1.667.6:1 CRScrew
6x-4 (Small chamber)1975350Late2.11 / 1.66101 ccScrew
6x-4 (Small chamber)1976350ALL2.11 / 1.6694 ccScrew
6x-4 (Small chamber)1977350ALL2.11 / 1.6694 ccScrew
6x-4 (Small chamber)1977400 (W72)200 hp2.11 / 1.6694 ccScrew
6x-4 (Small chamber)1978350ALL2.11 / 1.667.6:1 CRScrew
6x-4 (Small chamber)1978400 (W72)220 hp2.11 / 1.6694 ccScrew
6x-4 (Small chamber)1979400 (W72) 2.11 / 1.6694 ccScrew
6x-8 (Large Chamber)1975400Late2.11 / 1.66101 ccScrew
6x-8 (Large Chamber)1976400ALL2.11 / 1.66101 ccScrew
6x-8 (Large Chamber)1977400180 hp2.11 / 1.66101 ccScrew
6x-8 (Large Chamber)1978400180 hp2.11 / 1.66101 ccScrew
6x-8 (Large Chamber)1979400ALL2.11 / 1.66101 ccScrew
7F6 (Round Port)1972455 HO300 hp2.11 / 1.77111 ccPressed
7H11972350175 hp1.94 / 1.6680 ccPressed
7J21972400200 hp1.94 / 1.6696 ccPressed
7K31972400250 hp2.11 / 1.7796 ccScrew
7L41972455200 hp2.11 / 1.77114 ccPressed
7L51972455200 hp2.11 / 1.77114 ccPressed
7M41972455250 hp2.11 / 1.77114 ccPressed
7M51972455250 hp2.11 / 1.77114 ccPressed
X (Round Port)1973455 SD290 hp2.11 / 1.77111 ccScrew
X (Round Port)1974455 SD290 hp2.11 / 1.77111 ccScrew

Pontiac Head Ports - D-Port / Round Port

Here is an example of a Round Port Head (bottom), and a D-Port Head (top)

Pontiac 6X Cylinder Heads:

(Pontiac 6X Cylinder Head Example)

The 1977-1979 Pontiac Trans Am T/A 6.6 (W72 Performance Package) engine used different heads than the base 6.6 Litre Pontiac motor. The head code for each of these applications is “6X-4” (P/N 500795). The smaller chambered 350-cid 6×4 heads measured between 91cc and 93cc. The base 6.6 litre used the larger combustion chamber 6×8 heads (P/N 500798) that measured between 98cc and 101cc. The smaller chambered 6×4 heads helped boost the compression ratio from 7.6:1 to an advertised 8:1.

The W72 6X-4 heads can be identified conclusively by the small #4 machined on the bottom of a small ridge that protrudes from the head. It’s located between the front and center exhaust ports directly above the spark plugs, in front of the temperature sensor. You’ll probably have to scrape off the paint, as the “4” is stamped INTO the face of the machined pad. While you’re at it, take a look at the valve covers; all W72 motors originally came with chrome valve covers.

Other Pontiac Cylinder Head Examples:

(This is a Pontiac 96 Round Port Head) Note the '9' and '6' on the middle exhaust ports)

(B191 means that this head was cast on February 19, 1971 - The '1' could also be 1961, but '96' heads were only used in '68 & 71)

1968 R96A Ram Air II Heads: (Submitted by reader):

Was looking at the cylinder head listings for a customer project I'm just getting into when I noticed something about my own heads that I'd like to bring to your attention. The 1968 RAII heads should be called out by their full casting code which is R96A, not just 96. The R and the A are cast on each end exhaust port, and the 96 is cast on the center port. While it's true that it is not very difficult to distinguish the 1968 round port head from the "other" 96 head from 1971, what's interesting is that some very early RAII round port heads only had the R and the A on them and the 96 was missing. So while it's true that these heads have become commonly known as #96 heads when you see them referenced in magazine articles or online forums, in fact they should be more properly known as the "R - A" heads (with the 96 thrown in as a bonus) since EVERY one of these head castings had the R and A in place but not all had the 96. Of course we can't back up time and redo the million magazine articles that have been written about these heads, so that's life. But in short I'm proposing that for a formal list like yours, you consider updating it to show the full callout for these heads - R96A. I have a set of these (cast Jan 21, 1968) as the centerpiece of the engine currently in my own '66 GTO. Always gets lots of attention when true Pontiac people realize what they are. 

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