I have the L33. To name a few, some call it the "B" motor, SSR motor, and "The High Compression 5.3". Chevy's brochure calls it the H.O. 5.3.
I am interested in any info I can get on the heads. The Brochure states" With higher flowing heads". I am told they are LS6 heads.

Cast into the drivers side head at the front is "799".
On the passenger side, dimpled into the head just before and above the exhaust port is "62492497".

Combustion chamber cc's would be nice for starters.

If you guys ever want to look at the dimples numbers and want to use your finger to move some dust, be carfull, thereis a RAZOR sharp edge just above it. WoW is it ever sharp on mine.

 

Who told you and was it in a post?

 

It was on the Old PA forum. It may be in the old search data base. I hear it is still accesable but do not know how to get at it.

I did copy one of the replies and saved it. There was some disagreement about it. That is why I am posting on it again. I want to know what they did in the order of "Higher flowing heads".

Here is what I saved from one of the replies. My numbers are not there but they are for 2002-2003.

12564824 Head Assembly, 2002-2003 RPO LS6
This cylinder head is used on 2002 Corvettes with 405 HP RPO LS6. The LS6 cylinder head can be used on any Gen 3 design V8 block. This LS6 head is emission legal on the 2002-2003 Corvette only.

The casting number is 12564243.


It includes the following items:
12564825 Head - Bare
12565313 Valve Spring
10166344 Cap, Valve Spring, capable of 550" lift cam
12565311 Valve, Intake, light weight
12565312 Valve, Exhaust, light weight, sodium filled, hollow stem
10166345 Key, Valve Stem
12482063 Oil Seal, Intake
12482062 Oil Seal, Exhaust

===============================
Block?
12561166 LS1 or LS6 Corvette Bare Block
This aluminum block is used on th 2001 LS6 Corvette.

Technical Notes: Uses casting P/N 12561168.

 

Call the dealer and get a PN for a L33 intake and exhaust valves,if they are different from the (243) Ls6 heads then the L33 heads are not Ls6 heads.I would be surprized if Gm used the light valves in the 5.3,but if they did that would be a good thing.

 

Might also want to check out LS2 heads since they are the same as LS6 heads without the light weight valves.

 

Anyone know the casting #s on a LS2 head?

 

From ls1tech - Cylinder Heads - #12564825
Same as the 2002-04 LS6 cylinder head, no changes on the bare head. However the LS2 engine uses the stock LS1 valves rather than the lightweight Z06 valves.

 

Then you wouldnt call the L33 heads Ls6 heads no more than you would call Lq4 heads L33 heads.

 

I guess it looks like the added flow chactoristics of the LS6's is there but not the lighter valves. I would not rev that high anyway. I would be very surprised if the L33 had such advances anyway. I'll take the flow.

And again the P\N number he shows (12564825) is not the same as mine (62492497) so.......?

What is up with the Cast in number of 799?