12621766 is THE 6.2L from like 2011 and-on. Whether it gets final machined for ls3/l99, lsa, ls9, that's the casting and sleeves they start with. The variety of applications above get finished differently (cap material, piston squirters, dowels under caps, dod holes drilled, etc.), but the casting is the final culmination/design of Gen 4 6.2l blocks. ...or at least that's what I was told..

 

So is the 1262 1766 the casting number, not the part number or are one and the same?

 

LSA & LS9 have piston squirters & are different than other 6.2s.
I have a LSA based motor I bought from a guy that worked @ LPE, he said they weld the holes for the holes for the squirters.
Is yours a DOD? Pretty sure most SUV 6.2s were DOD.
For the most part the majority of 6.2s are the same besides DOD, LS3s & pick up 6.2s didn't have it but most of the SUV & lower horse cars did.
I have an early Escalade 6.2 block in my garage, I'll get the #s on it & my LSA block.

 

I would be interested in what casing number is on your LSA block.

 

My LSA block has the same 766 # but supposedly they're cryoed
LSA block head bolt holes are tapped different, not as deep & ARP stuff is to long, Livernois has LSA head studs.
My early 6.2 is 12584724
With the piston squirters & the shallow head bolt holes I'd rather have a regular LS3 or pickup truck non DOD block.
My 2011 Sierra is a 6.2 truck, VVT non DOD

 

Why would DOD or VVT make any difference on how strong a block would be ? Is the oil routed different in a DOD vs VVT ?

 

I was just saying if I was looking for a block a non AFM/DOD would be my 1st choice.
I think they're all VVT, to remove the AFM/DOD there's additional parts & labor but if the block you have has it it's no big deal.

http://www.enginelabs.com/news/tech-quickie-plugging-ls-blocks-to-delete-afmdod/

 

I agree that on face value iron would be better. This build is going in a rear engine sand car, and every pound counts, we have ran cars with both iron and aluminum and we like the way the car handles and reacts better with the aluminum block. This last season we ran a stock caddy cts-v motor 6.2 with oem blower on pump gas, want to up grade for next year. Instead of tearing down this motor to just get the block, I want to sale it, and buy the same block, that is why I am trying to Get the ID correct. We are only going to a 4 inch stroke because of the short skirts. Which is oxymoronic cause short skirts make me want to stroke longer with a lot more than 4 inches. Also when you are my age a little power adder helps you stroke longer according to all the ads on TV, too much and you could stroke out, but what a way to go out.