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Which Cylinder Heads Came On Your TBSS

44K views 33 replies 23 participants last post by  sahl0026 
#1 ·
The Corvette forum was jumping today because one of us discovered that their LS2 with a build date of 10/2006 actually came with the Cylinder Heads coded #799, and not the standard #243 (casting number). This caused a big issue today because nobody can figure out why GM put different heads on a small batch of LS2's and then went back to the #243, and we don't know if there is any difference.

So, I checked my TBSS today, and really oddly, my TBSS has a #799 cylinder head on the passenger side, and a #243 cylinder head on the drivers side. The coding or Casting number is near the backside of the head on the passenger side if it's a 799, it would be near the front of the head on the passenger side if it's a 243. The reverse order for the drivers side. With a flashlight you can see both on our TBSS's pretty easily. Of all the confusion, I was the only LS2 that had one of each. I'm wondering if you all could take a look at yours and see which heads you have. The only 799's we have seen on the Corvette forum had build dates of 9/2006 and 10/2006. I'll try to get a link to what the discussion is. Of all the research they have done so far, the 799's were not meant for the LS2, but we haven't heard the results yet.
 
#5 ·
2007 SS owners check your heads!!!

Just wanted to let you guys know about a interesting topic going on over at the Corvette Forum about the wrong heads being put on some of the later 2007 vettes. The LS2 heads wich is the same as the LS6 head has a casting number of 243. Problem is that some of the LS2 have heads with a casting number "799" truck heads, wrong head!!!:weird:
I have checked mine and it has the 243 castings.:thumbsup:
A vette owner dynoed his vette with some mods and only pulled 345!!!
So far 5 07 vettes have this head :duh:
If you have this issue chime in.
 
#17 ·
one of each

I have a 07. It has a build date of 10/06. It has a #799 on drivers side and a #243 on pasenger side. I think that may be the oposite of CodyC6? Does seem very odd! I have a hard time believing that they could mix up a set of heads and not cause idle or other problems that would be noticable. Although I'll be talking to my dealership on monday!:hissy:
 
#19 ·
I found this info.

"If you have been watching my listings over the past month you have noticed that I am quickly becoming "the" source for clean 6.0L parts such as heads blocks and cranks, please check my previous listings and keep track of what I have coming up soon. Coming in soon are more 6.0L parts as well as other Gen III engines. Let me know what your looking for.

You are bidding on a core set of GM Gen III aluminum heads. Casting number 799 (same as 243), small chamber, Less than 10K Miles. H214 and B175 casting, 2005 model, excellent condition! Please check with your dealer to be sure this is the exact one for your application. May fit other applications, my description is only a guide and I cannot guarantee it is 100% correct, just what I found. Sold as-is!"

Found this doing a search on the heads. Also seen this same think on the vette site.
What do you all think of this info? Crap or truth???:confused:
 
#20 ·
The vette sites seem to believe is "much to do about nothing." Older castings that have been machined to newer specs. Pre production LS6 heads(799) machined to L33 specs (243) Casting #'s are just that... casting numbers. Not the specs the heads have been machined to. I think that there may be some bar codes on the heads that would tell the truth of there actual finished specs. I'm going to get my first oil change next week, (I've got 800 miles right now) and I'll grill the service adviser! Not that he'll know what I'm talking about!!!
Like I said earlier. The fact that two differant heads could be on the motor is crazy!:weird:
 
#23 ·
those heads are on our 07 tahoe and 06 silverado, both 5.3l, not 6.0l... my 06 tbss has 243's... i just cant see how the same casting can be used on two different displacements.



:weird:
In the Gen-III & IV motors GM has gone to changing piston dish sizes rather than head chamber dimensions to control compression ratio; it's cheaper in a manufacturing sense. Example in Silverados (Vortec motors) is the 6.0L LQ4 & 6.0L LQ9, they are identical except for the pistons, the LQ4 has less compression (low compression pistons) than the LQ9 to run primarily on 87-octane.

Mr. P.
 
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