Block Identification

So I bought a 6.5 block that I think is a 1997??

The numbers are: 12555506 and L136

Any help is greatly sppreciated

December 13, 1996.

Is it a good block? How does it fair as a 6.5? Squirt block?

Thanks

Lots of information in the "date code" sticky: https://www.thedieselpageforums.com/...ad.php?t=24325

I did read through the thread, and think this block was prone to cracks but cant zero in on exactly what I have. Squirt or no squirt. I'm assuming that if no cracks, it's a good block. I'm told that it was running fine when it was pulled.

Any information is greatly appreciated.

Late 1996 and early 1997 model year saw the introduction of the piston oil spray blocks. There was a fairly narrow window of near catastrophic failure percentages.

The non spray blocks were equipped with 1/2" oil cooler lines and the spray blocks got 5/8" lines.

Jim

All 6.5 blocks can crack at the various places in the bottom end web area in the middle 3 webs near the bolt holes.

Late GM blocks had issue near the top of the number 8 cylinder bore as well.

The only "Good blocks" are the ones made by/for AMG

2002 and later were/should be the good stuff.

This said...If you have a well seasoned block that is crack free you should have a good foundation to build on.

Gotcha, thanks for the info y'all!!! ]