Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

LS6 block 2004 revision

Thread Tools
 
Search this Thread
 
Old May 10, 2011 | 02:51 PM
  #1  
DAlgozine's Avatar
Thread Starter
Teching In
 
Joined: Nov 2008
Posts: 13
Likes: 0
Default LS6 block 2004 revision

I have done a search and can't seem to find the info I'm looking for.
I've heard that the 2004 + LS6 block was improved over past blocks. Specifically the oil passages. I know they use the shorter head bolts, and I've heard they require the LS2 rear cover, True ?? Can anyone confirm any other improvements, such as oil passages? I've heard that 2004 plus block has the same oil passage improvements as the Gen IV blocks??

I'm finding that new LS6 blocks for sale have a part number of 12561166 and previoius LS6 part number was 12561168. Any info??
Reply
Old May 10, 2011 | 11:06 PM
  #2  
theevette's Avatar
On The Tree
iTrader: (2)
 
Joined: Jul 2008
Posts: 152
Likes: 0
Default

I never heard that maybe you have been bs'd . I think everything changed in 05
Reply
Old May 10, 2011 | 11:08 PM
  #3  
01ssreda4's Avatar
TECH Senior Member
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (96)
 
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Default

They require a new front cover, because the cam sensor was relocated there.......and I have seen a 04 LS6 block use the old style head bolts.
Reply
Old May 11, 2011 | 07:58 AM
  #4  
DAlgozine's Avatar
Thread Starter
Teching In
 
Joined: Nov 2008
Posts: 13
Likes: 0
Default

Thanks for your input. Based on my research, the Gen IV blocks (2005 plus) have improved oil passages (which are cleary visible ,require the following changes to be used in an LS1 type car:
New GM LS2-Specific Valley Cover
New GM LS2 Timing Cover with Cam Position Sensor
Knock Sensor and Cam Position Sensor Extension Harnesses for a Direct Fit into LS1 vehicle!
LS2-Specific Timing Set
GM LS2-Specific Lifter Trays

It appears the 04 plus LS6 block may share some of the re-design of the Gen IV, but I can't confirm. My understanding, non of the above parts list is needed for the 04 LS6 block installed into an LS1 car.
So, why the part number difference and what is the difference from pre and post 04 LS6 blocks?

Here is a photo form a book with some good info about LS engines (How to Build and Modify GM LS-Series Engines, by Joseph Potak)

Top image is rear of Gen III block and bottom is rear of Gen IV block.
Notice Gen IV block has newer design lifter oil gallery, Area is opened up to provide unrestricted oil flow to both lifter banks (compared to previus) This update equalizes any discrepencies in iol flow that may show up under demanding conditions.


Last edited by DAlgozine; May 11, 2011 at 08:45 AM.
Reply
Old May 11, 2011 | 08:09 AM
  #5  
01ssreda4's Avatar
TECH Senior Member
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (96)
 
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Default

This thread has an excellent post in it from LPE:

https://ls1tech.com/forums/pcm-diagn...24x-wheel.html
Reply
Old May 11, 2011 | 04:07 PM
  #6  
5.3LJimmy's Avatar
10 Second Club
20 Year Member
iTrader: (10)
 
Joined: Jun 2004
Posts: 2,279
Likes: 1
From: Napoleonville, LA
Default

Originally Posted by DAlgozine
The top image is a 97-98 block. All 99-up blocks are designed like the bottom photo for the rear oil passage.
Reply
Old May 11, 2011 | 05:26 PM
  #7  
NasbaGoat's Avatar
Staging Lane
 
Joined: Oct 2008
Posts: 64
Likes: 0
Default

if Feb of 2004 they went to a different headbolt setup.... could be 1 reason for the part # difference...
Reply




All times are GMT -5. The time now is 04:34 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE