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Debbie Harris's 1969 Grand Prix

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Identifying my motor


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Hey guys. I have a 63 Lemans and was told it has the original motor. When I have tried to verify this using the stamps on the block they do not match any numbers for that year that I can find. Any ideas?

Mike

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I have run into this with Chevelles. The motor could be original to the car but it could have been a warranty replacement engine 12/24 months after the the car was bought. Sometimes the casting numbers can be difficult to track.


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Hey guys. I have a 63 Lemans and was told it has the original motor. When I have tried to verify this using the stamps on the block they do not match any numbers for that year that I can find. Any ideas?

Mike

Help us a little....what motor are you running in your Lemans? Is is a straight four, a Buick nail head, or a Pontiac V8? This will make a difference were to look for the VIN number on the engine.

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Look for the casting number on the block. A '63 326 V8 will be 548211. A '64 326 is 9773153. A '65 & 66 326 is 9778840. Casting codes from 1955 to 1963 are on the passenger side of the block. From 1964 to 1967, they are on the distributor pad (except for the 421). Casting codes for from March 1967 on are found on the rear of the block just behind the number 8 cylinder. This will confirm the original displacement of the engine and the year of the block was made. It will not confirm it is the original engine.


 


Now there should be a block code. It roughly corresponds to the body/transmission/carb/engine combination. So for a '63 A-body with a 326, the possible codes can be. These can be found on the front of the block below the passenger side head.


 


 



Code

Car

Year

CID

HP

Trans

RPO

VIN

Carb

Block Cast

Main

Notes

590

A-body

63

326

280

Powerglide

L-76

 

1x4

548211

2

HO

68X

A-body

63

326

250

3-speed

L-30

 

1x2

548211

2

 

600

A-body

63

326

260

Powerglide

L-30

 

1x2

548211

2

 

690

A-body

63

326

250

Powerglide

L-30

 

1x2

548211

2

 

70X

A-body

63

326

280

4-speed

L-76

 

1x4

548211

2

HO

71X

A-body

63

326

260

3-speed

L-30

 

1x2

548211

2

 

 


 


 

Date Code

The date code is cast on the distributor pad. It is a 3 or 4 digit code. The first digit will be a letter. A=January, B=Febuary, 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 build date of the engine will be sooner than the build date of the car. If it is older than the build date of the car, the engine has been replaced (it is possible it a service replacement).
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