Identifying junkyard 6.0 liters

[Badass69]

........

 

[Hogg]

Ya, its an issue if the vehicle or VIN is unavailable.
You are correct about the pull the plug, try and feel the dish of the piston for the LQ4, flat tops for the LQ9.

If its a 6.0 from a 1500HD, 2500, 3500 its an LQ4. Sierra AWD C-3 and GMC Denali pickups use the same LQ4 but are rated at 325hp, this extra power comes from PCM tuning.
LQ4 came about with iron heads for MY 99-00, then went to aluminum heads for MY 01+. For MY2002, the LQ9 was added to the lineup for Cadillac models.
The 1st use of an LQ9 in a 2wd 1/2 ton pickup truck was for MY2004 as part of the very very limited B4V "Texas Truck". These were only sold in Texas and surrounding states. There were only 957 of these "B4V" trucks built. They are ALL 2wd, 4 speed 4l65e auto trans, 10 bolt 8.625" ring gear, semi floating-rear axle assemblies, with torsion bar front suspensions, 20" rims that are specific to the B4V trucks(different than the SS Silverado) and came with tires that were specific to the B4V truck(again different than the SSS) and traction control. These trucks arrived at the dealership without the distinctive "VHO" decals, these were deal installed items.
2005 saw an expansion in B4V distribution, you coudl get them in any area of North America. The major differnce for MY2005 was the dropping of the 10 bolt rear, and adding the beefy 14 bolt 9.5" semi-floating rear axle assembly. If only they made these trucks in a reg cab/shortbox version. I would have one in the driveway, but alas GM bever did this.

After MY 2002 GM started coating all their GEN 3 pistion skirts in an attempt to reduce noise. The LQ9 always had the better rods and thermal barrier coated piston tops, and as you stated all GEN3 LQ4/9's shared the better rods for MY 2005 for sure, some late 04's MAY have gotten them as well.

On an engine dyno, LQ4 with full PCM tune, the strap down an LQ9 and do a full PCM tune, the engine output will be within 5 hp. With full PCM tune, dyno headers, dyno exhaust these engines will twist just shy of 400 engine dyno hp.
The only difference that will affect power is the 9.4:1 vs. 10:1 CR difference as you mention.

I am curious as well, if and where the VIN is on a GEN 3 engine as well.

peace
Hog

 

[300King]

I don't believe you will find a VIN on LS motors. Look for the number 317 stamped on the heads.

 

[300King]

Just passing along what I have been told. I'm interested in what you find out.

 

[monstar_est87]

O dang..! I want an LQ9..!

 

[stuntmanray385]

O dang..! I want an LQ9..!

me too!!!

 

[Butch]

Thread has been cleaned of trash, I have both an 02 5.3 and 04 LQ4 sitting on stands right now, I'll look for any identifying marks on them later, as well as the 8.1L which is really just a modern big block.

 

[Badass69]

There is a laser etched dot matrix number on the drivers side rear of the block above the oil filter area in the back. Mine is very hard to discern even clean and highlighted, so it comes up as a 4.8 2wd 05 Tahoe at GM. Problem is I know the engine is an LQ9 ( kinda hard to mistake it opened up plus the big 6.0 on the block and 317 heads make it a 6.0 liter anyhow) so I have a digit wrong. Either way if you look it is the last 8 characters of the donor vehicles VIN number.