How do you decipher date code on block?
Apr 2, 2008 | 08:06 AM
#1
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TECH Junkie
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From: Minneapolis, MN
How do you decipher date code on block?
I'm trying to figure out what year my 6L block is and I'm wondering if GM has changed anything in the way they label the dates on the block from years ago. The old way of telling what day and year the block was made was like this.
F268
This would translate to F(count months = 6) June then the 26th day of the 8th year of the decade. This could be 1968 or 1978.
Going to my 6L now, it has a date code (or so I think it's a date code) cast in the front of the pass side cyl head of D224. Does this mean it's an April 22nd 2004 block? If it does then my block was built just 3 days after my truck was born. Sick I know
F268
This would translate to F(count months = 6) June then the 26th day of the 8th year of the decade. This could be 1968 or 1978.
Going to my 6L now, it has a date code (or so I think it's a date code) cast in the front of the pass side cyl head of D224. Does this mean it's an April 22nd 2004 block? If it does then my block was built just 3 days after my truck was born. Sick I know
Apr 2, 2008 | 09:04 PM
#3
Apr 2, 2008 | 09:07 PM
#4
Joined: Apr 2004
Posts: 16,820
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From: In a van DOWN BY THE RIVER
Bud- speaking of fenders you have anything ya wanna sell????
John
Apr 2, 2008 | 09:24 PM
#5
Sorry man, I'm keepin what I've got...a black 95 American P-Bass (my favorite), A sunburst Japanese P-Bass (can't remember what year...80's or early 90's I think), and a black Mexican P-bass that I keep around for when kids come over and want to play (not worth anything lol)
-Billy
-Billy
Apr 2, 2008 | 10:24 PM
#7
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TECH Junkie
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From: Minneapolis, MN
Since there is some interest in this I will teach you guys something about spotting old chevy parts so you're well versed when it comes to carshows/swap meets and junkyard. The photo below is a Cylinder head for a 1970 LS6 454. 
What I want you to look at is the A19-70 What this tells you is A(1st letter of the alphabet = january) the day (the 19th) and the year is 1970. If this cylinder head would have been made in 1968 or 1969 the year would be a single digit (example: B039) would mean an head or engine block made (B=2nd month) the 3rd day and the year 1969. After 1969 they went to a 2 digit year. When they went back to a single digit year designation I forget. So if everyone goes out to their truck, and look at the pass side deck surface in front of your head you should see what I think is the date code. If you have the original engine in your truck, it should have been produced within a few weeks of your truck being produced (obviously not after unless it was replaced under warranty).
What I want you to look at is the A19-70 What this tells you is A(1st letter of the alphabet = january) the day (the 19th) and the year is 1970. If this cylinder head would have been made in 1968 or 1969 the year would be a single digit (example: B039) would mean an head or engine block made (B=2nd month) the 3rd day and the year 1969. After 1969 they went to a 2 digit year. When they went back to a single digit year designation I forget. So if everyone goes out to their truck, and look at the pass side deck surface in front of your head you should see what I think is the date code. If you have the original engine in your truck, it should have been produced within a few weeks of your truck being produced (obviously not after unless it was replaced under warranty).
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Apr 2, 2008 | 10:32 PM
#8
Hmmm, I'm going to start recording some of the numbers on my engine and heads when I get a chance. Maybe I can get my butt over to my dad's shop and scope out my LQ9 longblock...it's supposed to be out of an 03 SS with 27K. I'll have to keep this thread in mind or make up a quick cheat sheet...
