Mystery 6.0L Core ???
 

I recently picked up an engine core and I am confused as to what it is...

So far It is clear that the engine is a Gen IV 6.0L, build date November of 2007 and VIN that went into a 2008 vehicle.
It has DOD/ AFM lifters and valley cover with NO VVT.

What is ODD is that it had Cathedral port heads on this engine.
I stupidly did not look at the cylinder head casting number before taking the short block home.
If I remember correctly, the heads looked like the larger chamber 317 heads that were on Gen III LQ4 engines.

All Gen 4 6.0 have rectangle port heads...so if it is Gen 4 someone swapped the heads and the only Gen 4 6.0 with AFM was the Aluminum L76 from the NNBS Vortec Max Trucks...also on the back of the block it will tell you the displacement and if it’s a Gen 4...example of my L96...post some pics for us


https://cimg4.ibsrv.net/gimg/ls1tech...d481c98e1.jpeg

Was the engine in a vehicle when you first saw it? I wonder if someone used a Gen IV 6.0 short block to rehab a Gen III engine in an older truck, and left all the DOD junk in there.

Is it a iron or aluminum block? What casting head #? What color crank sensor?

The later LS2s were technically Gen 4 and had cathedrals.
The LFA and LZ1 were hybrid versions of the LS2. 243s with flat tops, VVT, AFM.

I'm starting to get information coming in...

I went back to the dealership that had the engine core.

The heads that I left behind are 243 castings.

I am waiting on a break down of the last 8 of the VIN... so far I know the engine came from a plant in Australia and the vehicle is a 2008 Pontiac or GMC of some type...

Is it POSSIBLE that in 2008 a Pontiac G8 could have had a L76 engine with DOD and 243 heads?

Or was the a 2008 GMC truck with the L76 vortec-max as stated above with 243 heads?

What confuses me, is I was under the impression L76 engine had VVT... The engine core had no VVT cam/ timing set/ timing cover/ actuator/ or electrical...

No, the L76 had rectangle ports.

Is the block you have iron with cathedrals? There were no Gen 4 iron/cathedral combos from the factory.

No... That would make too much sense.

It is aluminum...

Looking at the engine core, one would think it to be an LS2 however it has DOD... This is why I call it the MYSTERY engine core.

The LFA was available in 2008 models. Its an aluminum/cathedral engine with DoD.

Now that is interesting! You are certain the LFA did not use VVT?

Should that be the case, you may be correct.

Do you have a picture of the engine?

The LFA had VVT.

I can a photo of the cylinder block... what exactly would you want to have a photo of?

Here is the only one I have at the moment...

Just let me know specifically what you are looking for.

https://cimg4.ibsrv.net/gimg/ls1tech...e5c38e74c2.jpg

As of today, it now looks like this...


https://cimg6.ibsrv.net/gimg/ls1tech...3235aa0183.jpg

Once it is stripped that bare, the RPO code becomes irrelevant. Once you strip an LM7 block down to nothing, it becomes the base that was used for 4 different RPO codes. Same for several other engines.

Measure the bore. Sounds like a 5.3.

Seems a little excessive considering it will say either 5.3 or 6.0 directly on the block.

This is true ha.

Yeah, the block has two locations cast as "6.0L" and the bores measured 4.0004" to 4.0010" ...Obviously a 4" bore engine.

They are now approximately 4.005". I just ordered new JE forged flat top pistons with dual valve reliefs and a Total Seal ring set for this engine.

I also ordered a set of Manley 6.125" pro-series I beam connecting rods and a Callies DragonSlayer 4" crankshaft.

Are many of you guys running perfectly "square" engines?

I was concerned it was an odd-ball factory mistake or who knows what else... Maybe something Rare?

So far it is looking like a 6.0L from a GMC Yukon Hybrid.

I'm still waiting on more information...

Any recommendation on cylinder heads for this displacement engine? I have up to $3,000 to spend on heads less springs/ retainers/ locks and machine work.