What im looking for...I have a 2000 c5 and i am wanting to build a motor for fun for my car. I want to go iron block because its going to be built stout and run NO2 on it.

Cutting to the chase. All i want is the part no. to the best iron block lsx suited to fit my c5. im wanting to stroke it out to like a 415.


All i need is a bare block part no. can anyone give me this?

 

If you want the baddest LS block, here ya go:

19166454
LSX Bowtie Block (Standard Deck)• 3.990" finished siamese cylinder bores
(ready to be honed to your specifications)
• 9.26" semi-finished standard deck height
(ready to be decked to your specifications)
• Max 4.250" recommended stroke
• Capable of 364 to 482+ cid
• Orange powder coat finish
• Accepts all Gen III & IV LS heads, cranks, cams, etc.
• Approximate finished weight: 225 lbs.

 

Here is the LQ9 6.0L block:

12572808
LQ9 Cast Iron 6.0L Bare Block
• Direct replacement for 1998–2004 LQ4 and
LQ9 Truck and SUV 6.0L
• Production cast iron block
• Production oiling system
• 6-bolt iron main bearing caps
• 9.240" deck height
• Use only LS1, LS6, LS2 or L92 cylinder heads
• 4.00" finished bore (101.6mm)
• No provision for ‘Active Fuel Management’
• Great for stroker cranks for even more cubes
• Tested to over 500 horsepower!

 

If you are stroking it out, the LQ4 and the LQ9 will be identical, the LQ4 being more easily found and usually cheaper.

Here is some numbers that I got:
12551364
12573581
12577184

I know the block number on my LQ4 was the first one (12551364), haven't verified the others cause I don't have my book at work.

 

Here are all of them

 

That list is not complete. LQ4 isn't even on it. And I had a LQ4 block with a part # 12551364.

 

You can't buy a new GM LQ4 block. The numbers I listed are all of the new available blocks. There is no difference between the LQ4 and LQ9 blocks anyways. If the OP wants to quick ID a 6.0L, just look at the left front of the block with the accessory drive stuff out of the way and 6.0L is cast into the block surface.

 

He didn't mention anywhere that he was buying it new.

 

Lq9 Block,eng (cstg) 12551364
Lq4 Block,eng (cstg) 12551364
L76 Block,eng (cstg) 12568952
Ls2 Block,eng (cstg) 12568952
L76 Block,eng (cstg) 12577461
L92 Block,eng (cstg) 12584724
Ls3 Block,eng (cstg) 12584724

 

question why is the Lq9 listed as 3.98 bore? ls2 listed at 4.0 thought they were the same by that the the lq9 is .012 smaller which isn't much but still odd.

 

The LQ4/9 is a 4" bore IIRC.

 

It is a 4" bore. I will go ask someone about the discrepency, one page show 4" the chart shows 3.98". Perhaps because it an iron block and the LS2 is aluminum, they give you more honing leeway. Or it could just be a good old fashioned typo.

 

Probably just a misprint My lq4 measures 4" or they gave the piston size but even that still a little small.

 

OK i know LS1,2,3,6,7 but dont know all the trucks above the L92 is a 6.2 alum block-pretty sure - would someone chime in on the list above 5.3-6.0-6.2 and if theyre alum or iron? sorry pretty much a noob Q here

 

Lq4/Lq9 are iron L76 is the aussie Ls2 L92 is the alumuminum 6.2 truck ls3 is the same thing diff intake better valve train and higher compression.

 

so lq4 and lq9 are iron - 5.3 or 6.0?
L76 is same as ls2 but aussie so out of a GTO?
L92 is 6.2 truck whats the vin code ? i know a 6.0 is "U" the vin code stuff helps me when at boneyard when we find burnt veh ect
sorry didnt mean to hijack , tryin to be smarter every day

 

LQ4/9 is a 6.0 liter.
The L92 and the LS3 are identical castings.

 

LQ4 - vin U
LQ9 - vin N
L76 - vin Y Pontiac G8
L92 - vin 8

 

I have a 6.0 block with cast number 12551364 (GM-5MC0)
How can I tell if its a lq4 or lq9. I was told it was a 2006 6.0 from a escalade.

 

All the Escalades came with LQ9's.
If you didn't know the origins, the only way to tell the difference would be to pull the heads and look at the pistons. LQ9's had flat top pistons and LQ4's had dished pistons. The LQ4 has a compression ratio of 9.41:1 and the LQ9 had a CR of 10.x:1. If you bolted on a pair of 243's on to each, slid in a nice cam, added some bolt-ons, maybe a dash of spray...you'd have a mean machine.