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Old 08-23-2019, 01:52 PM   #1
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SBC date code

Hi, I’m looking for some help deciphering the age of this 283 block.

It has a forged crank and the suffix code has been machined off.

All sources I’ve checked have said date codes were:

“Letter” “Number” “Number”
Location Month Year (last digit of year)

This appears to have “Letter” “Letter” “Number” “Number”

Not sure what the “M” means.

Any help is appreciated.
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Old 08-23-2019, 03:23 PM   #2
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Re: SBC date code

Does this help?
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Old 08-24-2019, 01:12 AM   #3
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Re: SBC date code

What you are seeing as a letter I at the beginning , I think is just a part of the tag used in the mold. IMO this block date code is A 2 5. That translates to January 2 1965
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Old 09-02-2019, 10:00 PM   #4
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Re: SBC date code M means It was cast in Mexico.
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Old 10-02-2019, 01:17 PM   #5
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Re: SBC date code

The casting no. shows 58-62 283.
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Old 10-03-2019, 07:13 PM   #6
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Re: SBC date code

The casting number 3756519 was only cast during the years of 1958 thru 1962;
The first number on the casting date is a "1" which would be 1961. year options would only be 8, 9, 0, 1, 2
The letter A would be for January.
The number 25 is the day of the month.

1 A 25 = January 25, 1961 with a casting number 3756519

I believe it would not be January 2, 1965 because this casting number was not cast in 1965.

Also, GM casting number 3556519 (283) was only cast during the years of 1958 thru 1961 not to be confused with the other one 3756519 (283) .....

++++++ January 2, 1965 was a Saturday and January 25, 1961 was a Wednesday.

This is only my opinion.....

Last edited by YoungPup1977; 10-03-2019 at 11:00 PM.
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