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Old Jul 28, 2012 | 10:48 PM
  #21  
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The 243/799 castings are superior in flow and overall design, and gains when swapping a stock LS1 head for a stock 243/799 head usually nets you somewhere in the neighborhood of an additional 15rwhp.
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Old Jul 28, 2012 | 11:13 PM
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Originally Posted by Keith_Shapiro
I'll tell you soon I just took my 806 heads off today and the 243's gone in this week
Ok cool I didnt really notice a diff when I put my 243s
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Old Jul 28, 2012 | 11:17 PM
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Originally Posted by crainholio
Any metal you remove from the combustion chambers will lower the compression ratio. Easy to get it back with milling, though.

Be aware it's very easy to create imbalances in airflow if you get crazy with the hand-porting. I only recommend polishing to remove the casting roughness in the ports for non-professionals (like myself). And flush 'n brush them thoroughly afterward to get all the abrasives and aluminum dust completely gone.

Leave the carbide burr to the pros who know what they're doing and can get all 16 ports to reasonably symmetrical volumes and airflows.
Ive done them before with my other car but I do knw what you meam... Just thats time patients and alot of grinding... I use a Sharpe pen and gaskets to get them the same
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Old Jul 28, 2012 | 11:25 PM
  #24  
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If it's a true ls6 head it will have sodium filled valves also
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Old Jul 28, 2012 | 11:28 PM
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Originally Posted by cory32690
If it's a true ls6 head it will have sodium filled valves also
Got them from my buddy zo6 vette so I dont gotta pull vavles to weight ... I hear thoses are more expensive right?
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Old Jul 28, 2012 | 11:32 PM
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Yes ad far as I no they only came off the z06 I believe they usually have yellow valve springs from the factory
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Old Jul 29, 2012 | 12:09 AM
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Originally Posted by cory32690
Yes ad far as I no they only came off the z06 I believe they usually have yellow valve springs from the factory
Thats true.. Thoses are the 1s I have
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Old Jul 29, 2012 | 05:45 AM
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Sounds like u got the good ones to me..send those off to ai or tea and when people ask u say it's still got stock heads on the car!!
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Old Jul 29, 2012 | 07:47 AM
  #29  
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Originally Posted by sjsingle1
many many differences..........the LS6 exhaust ports are D shaped for 1............
No they are not
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Old Jul 29, 2012 | 09:10 AM
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Originally Posted by redtan
No they are not
In fact they are:

LS6: The Ruthless Pursuit of Power

The LS1 exhaust port was also revised with the same goals: improve short turn radius and make cross-sectional area more consistent. The port exits were also given the pronounced D-shape that many racing cylinder heads use. The changes to the exhaust ports netted about a 10% improvement in high lift flow.
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Old Jul 29, 2012 | 09:16 AM
  #31  
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maybe get some ls1 heads for cheap to practice porting on.then work on the ls6 heads.
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Old Jul 29, 2012 | 11:08 AM
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Originally Posted by garygnu
maybe get some ls1 heads for cheap to practice porting on.then work on the ls6 heads.
Well ive done a few other heads with no problems but yes I suggest if you havent done them before practice on some other head im gonna port and polish my stock head and throw them up for sale
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Old Jul 29, 2012 | 11:09 AM
  #33  
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Originally Posted by cory32690
Sounds like u got the good ones to me..send those off to ai or tea and when people ask u say it's still got stock heads on the car!!
Lol thats very true
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Old Jul 29, 2012 | 12:00 PM
  #34  
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Originally Posted by cory32690
If it's a true ls6 head it will have sodium filled valves also
Incorrect. 01 LS6s didn't have them.

Originally Posted by cory32690
Yes ad far as I no they only came off the z06 I believe they usually have yellow valve springs from the factory

243/799 heads were used on many cars/trucks. Not all had yellow springs.
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Old Jul 29, 2012 | 12:29 PM
  #35  
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Originally Posted by chevybayboy
Ok cool I didnt really notice a diff when I put my 243s
what heads did you take off?? because i have the 806 castings and the 243's flow way more.
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Old Jul 29, 2012 | 01:38 PM
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In fact they are:

LS6: The Ruthless Pursuit of Power
So 243 heads have a round port and LS6 heads have a D shaped port? Cuz last time I looked, my 243s were round and aren't they the same as LS6s except for the intake valves?
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Old Jul 29, 2012 | 01:42 PM
  #37  
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Originally Posted by Keith_Shapiro
what heads did you take off?? because i have the 806 castings and the 243's flow way more.
I took off the 806s but did get tuned yet im waiting til im done with everything... I also like at the heads more closesly there is major differences vavles are way diff and so on.. I tried putting my 36# injectors in with no tune,lol doesnt work.. Now since I spun that lifter m trying to see if im goin to roll with the lifters I dont need a tray or ls7s with the ls2 tray so im kinda stuck
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Old Jul 29, 2012 | 01:44 PM
  #38  
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Intake runners are 10cc larger. 20-30cfm flow increase. Valves are lighter 2cc smaller combustion chamber which increases compression. Better combustion chamber design.
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Old Jul 29, 2012 | 02:18 PM
  #39  
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Originally Posted by redtan
So 243 heads have a round port and LS6 heads have a D shaped port?
If you're asking that question, it's time for more reading and less posting.

All factory LS6 heads were 243 castings, but not all used 243 heads came from LS6 engines.

The OP was asking about heads that came off an LS6 engine.
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Old Jul 29, 2012 | 05:03 PM
  #40  
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If you're asking that question, it's time for more reading and less posting.

All factory LS6 heads were 243 castings, but not all used 243 heads came from LS6 engines.

The OP was asking about heads that came off an LS6 engine.
I've done plenty of reading, and this is the first I'm hearing of a difference between a 243 off of an LS2 vs. a 243 of an LS6 being more than just the valves...that's why I'm asking.
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