6.2/6.5 Cylinder Block Date Code

[Robyn]

M031 December 3 of 1991 is most probable
The letters go from A being January through B C D E F and so on, I is not used as it looks like a 1 and ending with M being December.

03 being the third day and the 1 being 1991

Any and all 6.2 and 6.5 engines CAN have main line cracks.
Some casting series were far more prone to it though.

There is no way to predict if, when, which one or why.

The crack subject has been beaten about for years here and on other forums.

Metalurgy, stress risers that were not removed (Sharp edges) and on it goes.

The real late blocks made by AMG after they took over are far better.

The P400 6.5 is the gold standard. This engine has a complete built in girdle in the bottom end.

The older 6.2 engines did not see as much cracking, but it did happen.

Many of these engines will crack early in life and run a good long time without any issues, and the cracks are not discovered until the block is examined at rebuild.

[Phildo]

Hi there, I'm a new forum member and out if curiosity am after assistance in trying to ascertain production date for the 6.5l that was installed in my Nissan a Patrol/Safari late last year.

The number on the block that I can see is 516 on both sides of the V. The engine number stamped into the top of the block at the front if the V is 700215.

Any help appreciated.

[trbankii]

Have a line on a block to pick up as a spare. Not too many details yet, trying to get a date code so I know more. But it is a 12555506 block and has this “GEP / AMG” sticker on the valve cover. Need to check date code and whether it has the “triangles” in the valley. Should I be hopeful that I’m going to find them? I know the 506 blocks spanned the end of GM production (which had issues) into the AMG blocks (which are great).

[Robyn]

AMG BLOCKS
Have the Diamond in the valley (Actually 2 triangles back to back)
Date codes are found on the opposite side from the casting number

xx xx letter

The 2001 was the first real deal full AMG blocks and the letter is an H
I was not used
J is 2002 followed by K L M N O P etc

The first 2 digits are the month followed by the second two digits for the day

06 10 J = June 10th 2002

The 506 casting number has remained the standard casting number since AMG took over the 6.5


Good luck

Missy

[trbankii]

Yep, got all that from previous posts in this thread. I’m set to go look at it next Tuesday. I’ll report back on what date code and other information I find.

[Robyn]

Good luck on your quest

Missy

[trbankii]

Picked it up - triangles in the valley and date code of 01 21 *

The * may be an H or N - outside possibility that it is an M…

Have to clean it up a bit - and take it apart to see whether there are any issues inside.

[trbankii]

Ok, looking promising. Date code shows it as a 2006 and has the double triangles. I can turn it over, but I want to open things up to make sure that all is well inside the little beastie…

[Liftgate]

M031 December 3 of 1991 is most probable
The letters go from A being January through B C D E F and so on, I is not used as it looks like a 1 and ending with M being December.

03 being the third day and the 1 being 1991

Any and all 6.2 and 6.5 engines CAN have main line cracks.
Some casting series were far more prone to it though.

There is no way to predict if, when, which one or why.

The crack subject has been beaten about for years here and on other forums.

Metalurgy, stress risers that were not removed (Sharp edges) and on it goes.

The real late blocks made by AMG after they took over are far better.

The P400 6.5 is the gold standard. This engine has a complete built in girdle in the bottom end.

The older 6.2 engines did not see as much cracking, but it did happen.

Many of these engines will crack early in life and run a good long time without any issues, and the cracks are not discovered until the block is examined at rebuild.

Old thread, I know. I never did figure out my date code if in fact this is my date code: F047. Would that be June 04, 1997? It's a 6.5 N/A that replaced a 6.2 before I bought it. It's also a GM Good wrench crate engine. Any good? Thanks for your reply.

[Liftgate]

Old thread, I know. I never did figure out my date code if in fact this is my date code: F047. Would that be June 04, 1997? It's a 6.5 N/A that replaced a 6.2 before I bought it. It's also a GM Good wrench crate engine. Any good? Thanks for your reply.

Anybody? Help?