6.2 - 6.5 Diesel Mistaken ID

[solar mike]

I took a complete long block assemble to a very good machine shop in town, they looked up the casting #12552929 & date code A-1- 95.
They told me that this was a 6.5 made in 1995.
After hot tank & magging yes the heads are junk (any good leads on aftermarket heads?) They called and told me this block has a bore of 3.976, this means its a 6.2 with a 6.5 casting as I am being told.
Yes the block is crack free.
Has anyone seen this.
I have been told that the walls may be extra thich as to allow boring to a 6.5 size. This would require sonic testing of the walls though.
OR
Should I junk it & start with an aftermarket block?
Thanks

 

[dyeager535]

That number along with "diesel" in a yahoo search comes up with a bunch of info.

Here's one post:
http://www.gm-diesel.com/vbull/showthread.php?p=116674

It sounds to me like anything with a casting date of '94+ can't be a 6.2.

Who knows, could be castings for "crate" 6.2's or something. I'd probably want to check the bore myself, make sure they aren't mistaken and/or trying to fleece you somehow.

If it is indeed a '2929 with a '95 date casting AND 6.2L, doesn't seem like anyone knows about it, and it would be intersting if you could personally confirm the bore, date, and casting number. It would throw some of the "absolutes" being used to ID the motors out the window.

 

[tRustyK5]

I took a complete long block assemble to a very good machine shop in town, they looked up the casting #12552929 & date code A-1- 95.
They told me that this was a 6.5 made in 1995.
After hot tank & magging yes the heads are junk (any good leads on aftermarket heads?) They called and told me this block has a bore of 3.976, this means its a 6.2 with a 6.5 casting as I am being told.
Yes the block is crack free.
Has anyone seen this.
I have been told that the walls may be extra thich as to allow boring to a 6.5 size. This would require sonic testing of the walls though.
OR
Should I junk it & start with an aftermarket block?
Thanks

Keep the bore...you're not gonna gain a ton by boring it out to 6.5 anyways.

As for heads, there are a few aftermarket heads, most are 'offshore' and worth what you pay for em. reading what MaxPF here has gone through it sounds like ordering up a set of AMG heads is the most economical solution in the long run.

Check the diesel forum here...some really good info in there!

Rene