You may have an LS6 Block
08-31-2005, 08:55 AM
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You may have an LS6 Block I`m just trying to confirm this. I know a friend of mine has it. How can I tell If I do with out pulling the motor out.
This falls under PRESENT > Per GM High Tech July 2003……. 2001-2002 F-Body Owners- You may have a LS6 block.
John Douro, GM’s GEN III/IV block staff engineer, turned up some interesting facts about the Y and F body wonder mills.
There were 2 plants producing the LS1’s. Montupet factory in Canada, and Nemak in Mexico. Who had the better process? Believe it or not, Mexico. Seems Mexico is using some low pressure fan process which is considered a high-performance process.
So in 2001 GM needed the LS6 they went with Nemak in Mexico for the Z06 LS6 block.
What they were looking for in the LS6 block was bay to bay breathing. No one in PowerTrain confirmed HP gains, but they didn’t decline it either. Regardless of HP, the durability of the LS6 block had been increased dramatically over the LS1.
And now the good news. Mass production of the LS6 block allowed some to overflow to the F body cars. In 2001 10-15% of all produced F- cars got LS6 blocks. In 2002 25% of all F- cars got the LS6 block.
Heres how to tell of you are sporting a LS6 block in your 2001-2002 F- car. The block part number (12561168) is casted on the LEFT side at the back of the block of course, just below the cylinder head. You will need a flashlight and shop mirror on a stick most likely unless the engine is out of the car.
Theres some difference in the color of the aluminum block also. Montupet cast a real shiny block. Nemak is dull, but stronger.
Get this. All 2003 LS1 and LS6 blocks are the same stronger, dull block with the breathing holes drilled. Again part number ( 12561168 )..
This falls under PRESENT > Per GM High Tech July 2003……. 2001-2002 F-Body Owners- You may have a LS6 block.
John Douro, GM’s GEN III/IV block staff engineer, turned up some interesting facts about the Y and F body wonder mills.
There were 2 plants producing the LS1’s. Montupet factory in Canada, and Nemak in Mexico. Who had the better process? Believe it or not, Mexico. Seems Mexico is using some low pressure fan process which is considered a high-performance process.
So in 2001 GM needed the LS6 they went with Nemak in Mexico for the Z06 LS6 block.
What they were looking for in the LS6 block was bay to bay breathing. No one in PowerTrain confirmed HP gains, but they didn’t decline it either. Regardless of HP, the durability of the LS6 block had been increased dramatically over the LS1.
And now the good news. Mass production of the LS6 block allowed some to overflow to the F body cars. In 2001 10-15% of all produced F- cars got LS6 blocks. In 2002 25% of all F- cars got the LS6 block.
Heres how to tell of you are sporting a LS6 block in your 2001-2002 F- car. The block part number (12561168) is casted on the LEFT side at the back of the block of course, just below the cylinder head. You will need a flashlight and shop mirror on a stick most likely unless the engine is out of the car.
Theres some difference in the color of the aluminum block also. Montupet cast a real shiny block. Nemak is dull, but stronger.
Get this. All 2003 LS1 and LS6 blocks are the same stronger, dull block with the breathing holes drilled. Again part number ( 12561168 )..
08-31-2005, 09:17 AM
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thats the only way I think. Casting number. I know ls6 heads have the triangular patern under the exhaust ports but i dont think the block has any give aways.
08-31-2005, 03:15 PM
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Originally Posted by 777
https://ls1tech.com/forums/showpost....86&postcount=8 
It's only in the sticky.
It's only in the sticky.
Trending Topics
08-31-2005, 03:40 PM
#10
Originally Posted by MeentSS02
Yeah, I have the LS6 block...I put down 390 RWHP with a stock cam and stock heads just last night. I just have headers, true duals, a ported TB, and 85mm MAF. People say the blocks don't do anything, but I know better.
08-31-2005, 04:18 PM
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Originally Posted by MeentSS02
Don't be rolling your eyes at me...I just found my dyno graph. I scanned it real quick, so the quality isn't the best, but there it is in black and white (and red and blue).
415rwhp/392rwtq.
thanks!
08-31-2005, 05:09 PM
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"People say the blocks don't do anything, but I know better." 
you my friend have an extra 21rst chromosome.
it is just the block not any internals..just the block..so u think you got all that extra hp from...the block...cmon
you my friend have an extra 21rst chromosome.
it is just the block not any internals..just the block..so u think you got all that extra hp from...the block...cmon
08-31-2005, 05:24 PM
#18
Originally Posted by TOZ
Hey Some people don`t live here in LS1Tech. ok. I didn`t know this. So go have a beer and chill 
)
08-31-2005, 05:49 PM
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Aside from the casting number on the back you can tell by the "bullseye" on the front-top ridge above the waterpump. If the bullseyes are filled in then it's an LS6 type. That's the easy way to spot one.
The LS6 block doesn't add **** for power... period.
The LS6 block doesn't add **** for power... period.
08-31-2005, 09:15 PM
#20
Originally Posted by Tally TransAm
wow, this info was out like, what 2-3 years ago
OMG THEY HAVE HEADERS AVAILABLE FOR LS1's!!!!
OMG THEY HAVE HEADERS AVAILABLE FOR LS1's!!!!
hell i've got GMHPT mags from 03 that printed that info and they were behind as usual with there "breaking news". plus its been in the sticky for a year.
soon enough people are gonna start posting that the ls1 is underated
