The 1970-75 Camaros used a variety of blocks, cylinder heads, intake manifolds, exhaust manifolds, and waterpumps. In this article we will cover the identification of all these major engine components for all Camaro engines from 1970 through 1975. Both the information pertaining to each engine component and all pertinent information relating to each specific engine option are listed below the model year headings.
This 2nd Generation Camaro casting number breakdown list is the first to ever be published anywhere. These casting numbers were compiled from the original Flint Engine Plant build records and extensive Tonawanda records as well. What we hope to accomplish with this article is to familiarize you with how and where to look for casting numbers on the 1970-75 Camaros.
There were two plants that were casting cast iron parts for Chevrolet engines during this time period. These were the Flint, Michigan, and Tonawanda, New York, plants. All cylinder blocks, cylinder heads and cast iron intake manifolds cast in Saginaw, Michigan, for the Flint, Michigan, engine assembly plant would have a single-digit year date code. Engines assembled in Flint with the single digit year code were used in both passenger and Corvette applications. The Tonawanda engine plant cast their own castings at the engine plant. All Tonawanda engine component castings will have a “T” cast into the surface of the part to designate it as a Tonawanda casting.
Always remember that when looking for specific dates you need to keep the following in mind. First of all, try to verify the build date of your car. After the build date of your car has been verified, the actual dates you are looking for will be dated one to three months prior to the build date of the car. This time elapse allowed for the assembly of that engine, transport to the car assembly plant and installation of that engine in your car. There is documented proof that these engine plants would increase production leading up to possible strike periods, making it highly probable that many cars were built with engines way ahead (6 to 9 months) of thir respective build date. Another thing to consider if you have an original, untouched car, is to match the casting dates of the original parts still remaining on your car. This procedure can prove to be dangerous unless you can verify that these dates still coincide with the build date.
Block Casting Number Identification
The block casting number is the single most important number on a block because it will probably be the last number on a block to be altered or changed to counterfeit or misrepresent a block. The casting number is usually found at the rear left side of the block, on top of the bellhousing flange. The casting date codes are cast in an alphanumeric sequence. You should look closely at a block’s casting date because many blocks have been found that have been altered to represent an earlier or more expensive block. The first digit will usually be a letter code, which specifies the month the block was cast. Some casting dates have been found with all three digits represented as numbers, such as “345”, which decodes as March 4, 1965. These types of dates are not common in restoration circles. The month code letter designations are as follows:
A – January G – July
B – February H – August
C – March I – September
D – April J – October
E – May K – November
F – June L – December
The remaining digits in the date refer to the day of the month and year of the block casting.
Cylinder Head Casting Numbers
The cylinder head casting number is the single most important identifying feature on a head because, just like the block casting number, it will probably be the last characteristic to be altered or changed. The casting number is usually found in between two valves and the rocker arm studs underneath the valve cover. The casting date is usually found adjacent to the casting number. The casting date codes on small block cylinder heads can usually be found directly underneath the casting number. You should look closely at a cylinder head’s casting date because many heads have been found that have been altered to represent an earlier or more expensive cylinder head. The first digit in the casting date code will usually be a letter code, which specifies the month the head was cast. The month code letter designations are as follows:
A – January E – May I – September
B – February F – June J – October
C – March G – July K – November
D – April H – August L – December
The remaining digits in the date refer to the day of the month and calendar year of the head casting.
NOTE: It should be noted here that some engines will use the same casting number, but have a different valve size. Due to space limitations, the differentiating features of each cylinder head could not be included in this article. This information will be included in a forthcoming article. Also, the external identification symbols that are cast into the ends of each small block cylinder head could not be included in this article due to space limitations.
Intake Manifold Identification
All intake manifolds have a casting number which is found on top of the intake near the carburetor. This number is raised above the actual casting of the manifold and is relatively easy to find. Some intake manifolds have dates cast into the underside of the intake, some do not. Most intakes have complete dates and some have dates written in an alpha code i.e. Jan=A, Feb=B, March=C, etc.; then the day and year will follow the month alpha code. This dating system was sporadic at best. Always use the casting number to identify.
Exhaust Manifold Identification
All Chevrolet factory exhaust manifolds are cast iron. Since the manifolds are cast, the actual casting number and date are raised above the actual surface of the part. Most casting numbers are visible when the manifold is installed on the engine. The casting number location and casting date location will vary from year to year and sometimes manifold to manifold. Some manifolds will not carry a casting date at all. Casting date codes follow the same pattern as engine blocks, but some do not carry a year. The following is a breakdown of the casting date month codes:
Casting Date Month Code Identification
A – January G – July
B – February H – August
C – March I – September
D – April J – October
E – May K – November
F – June L – December
The number or numbers following the month code letter represent the day of the month that the manifold was cast. Sometimes, but not always present, the last number indicates the year.
Waterpump Identification
It has been established from all known data available at this time that the dating of waterpumps is as follows:
WATERPUMP # DATE INFO
SMALL BLOCK
#3953692 ALL DATED
#6263701 ALL DATED
BIG BLOCK
#3931065 ALL DATED
#3969811 ALL DATED
#6263707 ALL DATED
Casting date codes follow the same pattern as engine blocks, but some do not carry the year. The month code is always a letter, followed by a number which signifies the day. The last number signifies the year of production.
Example: B189
B: February
18: 18th day
9: 1969 (Refer to casting number to confirm)
Example: B1872 (Big Block Waterpumps Only Starting In 1970)
B: February
18: 18th Day
72: 1972
Casting Date Month Code Identification
A – January G – July
B – February H – August
C – March I – September
D – April J – October
E – May K – November
F – June L – December
1970-75 Camaro Casting Number Chart
1970 Camaro
307/200HP Block Casting #3970020 (2 Bolt)
Head Casting #3927185
Intake Casting #3927183 (Cast Iron)
Exhaust Manifold Casting #
RH – 3932376 w/o AIR
LH 3942529 w/o AIR
Waterpump Casting #3953692
350/250HP Block Casting #3970010 (2 Bolt)
Head Casting #3932441
Intake Casting #3916313 (Cast Iron)
Exhaust Manifold Casting #
RH – 3932376 w/o AIR
LH 3942529 w/o AIR
Waterpump Casting #3953692
350/300HP Block Casting #3970010 (4 Bolt)
Head Casting #3947041
Intake Casting #3965577 (Cast Iron)
Exhaust Manifold Casting #
RH – 3932376 w/o AIR
LH 3942529 w/o AIR
Waterpump Casting #3953692
350/360HP Block Casting #3970010 (4 Bolt)
Head Casting #3973414
Intake Casting #3927110 (Aluminum)
Exhaust Manifold Casting #
RH – 3946826 w/AIR
LH – 3942527 w/AIR
Waterpump Casting #3953692
402/350HP Block Casting #3969854 (2 Bolt)
Head Casting #3964290
Intake Casting #3955287 (Cast Iron)
Exhaust Manifold Casting #
RH – 3909879
LH – 3916178
Waterpump Casting #3931065 (Early)
#3969811 (Late)
402/375HP Block Casting #3969854 (4 Bolt)
Head Casting #3964291
Intake Casting #3963569 (Aluminum)
Exhaust Manifold Casting #
RH – 3909879
LH – 3916178
Waterpump Casting #3931065 (Early)
#3969811 (Late)
1971 Camaro
307/200HP Block Casting #3970020 (2 Bolt)
Head Casting #3986339
Intake Casting #3973465 (Cast Iron)
Exhaust Manifold Casting #
RH – 3973432 w/o AIR
LH – 3989043 w/o AIR
Waterpump Casting #3953692
350/245HP Block Casting #3970010 (2 Bolt)
Head Casting #3973487
Intake Casting #3973467 (Cast Iron)
Exhaust Manifold Casting #
RH – 3973432 w/o AIR
LH – 3989043 w/o AIR
Waterpump Casting #3953692
350/270HP Block Casting #3970010 (2 Bolt)
Head Casting #3973487
Intake Casting #3973469 (Cast Iron)
Exhaust Manifold Casting #
RH – 3973432 w/o AIR
LH – 3989043 w/o AIR
Waterpump Casting #3953692
350/330HP Block Casting #3970010 (4 Bolt)
Head Casting #3973487 or #3986316
Intake Casting #3959594
Exhaust Manifold Casting #
RH – 3986330 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #3953692
402/300HP Block Casting #3969854 (2 Bolt)
Head Casting #3993820
Intake Casting #3955287
Exhaust Manifold Casting #
RH – 3989310
LH – 3989343
Waterpump Casting #3969811
1972 Camaro
307/130HP Block Casting #3970020 (2 Bolt)
Head Casting #3998991
Intake Casting #6262936
Exhaust Manifold Casting #
RH – 3959562 w/NB2
3973432 w/o NB2
LH – 3989041 w/NB2
3989043 w/o NB2
Waterpump Casting #6263701
350/165HP Block Casting #3970010 (2 Bolt)
*Head Casting #3973487 (Early)
#3973487X/#3998993 (Late)
Intake Casting #6263752 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/NB2
3973432 w/o NB2
LH – 3989041 w/NB2
3989043 w/o NB2
Waterpump Casting #6263701
350/175HP Block Casting #3970010 (2 Bolt)
*Head Casting #3973487 (Early)
#3973487X/#3998993 (Late)
Intake Casting #6263751 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/NB2
373432 w/o NB2
LH – 3989041 w/NB2
3989043 w/o NB2
Waterpump Casting #6263701
350/255HP Block Casting #3970010 (4 Bolt)
Head Casting #3998916 (Unverified)
Intake Casting #3959594 (Aluminum)
Exhaust Manifold Casting #
RH – 3986330 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
402/240HP Block Casting #3969854 (2 Bolt)
Head Casting #3999241
Intake Casting #6263753 (Cast Iron)
Exhaust Manifold Casting #
RH – 3989310
LH – 3989343
Waterpump Casting #6263707
* NOTE: IT IS UNCLEAR WHY THERE SEEMS TO BE AN USAGE OVERLAP FOR THESE TWO CYLINDER HEADS. UNTIL MORE PRECISE DATA SURFACES, BOTH HEADS ARE TO BE CONSIDERED CORRECT FOR BOTH APPLICATIONS.
1973 Camaro
307/115HP Block Casting #3970020 (2 Bolt)
Head Casting #3998993
Intake Casting #6771061 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
350/145HP Block Casting #3970010 (2 Bolt)
Head Casting #3998993
Intake Casting #3997773 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
350/175HP Block Casting #3970010 (2 Bolt)
Head Casting #3998993
Intake Casting #3997771 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
350/245HP Block Casting #3970010 (4 Bolt)
Head Casting #330545
Intake Casting #3997771 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
1974 Camaro
350/145HP Block Casting #3970010 (2 Bolt)
Head Casting #333882
Intake Casting #340266 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
350/160HP Block Casting #3970010 (2 Bolt)
Head Casting #333882
Intake Casting #340261 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
350/185HP Block Casting #3970010 (2 Bolt)
Head Casting #333882
Intake Casting #340261 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
350/245HP Block Casting #3970010 (4 Bolt)
Head Casting #333881
Intake Casting #340261 (Cast Iron)
Exhaust Manifold Casting #
RH – 3959562 w/AIR
LH – 3989041 w/AIR
Waterpump Casting #6263701
1975 Camaro
350/145HP Block Casting #3970010 (2 Bolt)
Head Casting #333882
Intake Casting #346260 (Cast Iron)
Exhaust Manifold Casting #
RH – 346248
LH – 346247
Waterpump Casting #6263701
350/155HP Block Casting #3970010 (2 Bolt)
Head Casting #333882
Intake Casting #346249 (Cast Iron)
Exhaust Manifold Casting #
RH – 346248
LH – 346247
Waterpump Casting #6263701
