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This download from Vettemod.com is a complete engine service manual. Membership to their site is required, but there is some reall neat stuff other than this manual for those that just like stuff.

www.pleasurecraft.com/manuals/L510016.pdf

Enjoy!
 

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Nice one, been looking for this for a while now. Now I need a car for my LQ9 to be swapped into.
 

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What exactly is an LQ4/LQ9?
They are iron block truck motors. The LQ4 is the lower compression ratio (9.4:1) motor used in the 2500HD up till 2007. The LQ9 is the high output higher compression (10.4:1) 6.0L used in the caddy escalades and SS trucks. The only difference between the two is the pistons. The LQ4 has dished and the LQ9 has flattops. Also the LQ9 has the better LS2 rods. Also GM did have an all Iron version of the LQ4 with iron heads in 99 till 2000. Then it went with aluminum heads as well.

These are the poor mans LS2's!:)
 

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LQ9's were also installed in the V-Max and Texas VHO's option in trucks up to 2006 or 2007.They are strong runners and have a lot of torque.
 

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Texas VHO's?

LQ9's were also installed in the V-Max and Texas VHO's option in trucks up to 2006 or 2007.They are strong runners and have a lot of torque.
What are Texas VHO's? I have a 2004 Silverado 2-wheel drive with the factory Performance package that I picked up new in Texas. I wanted a 2-wheel drive with the same driveline as an SS. I couldn't find any of these trucks anywhere except the southwest. It has the 6.0. & most of the options that come on the Silverado SS except the all-wheel drive & the grille, painted bumpers, etc. How do I find out if it is an LQ4 or an LQ9?
 

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What are Texas VHO's? I have a 2004 Silverado 2-wheel drive with the factory Performance package that I picked up new in Texas. I wanted a 2-wheel drive with the same driveline as an SS. I couldn't find any of these trucks anywhere except the southwest. It has the 6.0. & most of the options that come on the Silverado SS except the all-wheel drive & the grille, painted bumpers, etc. How do I find out if it is an LQ4 or an LQ9?
They are special packages that were basically like SS trucks, GM made them for the south before the V-max's came out.
One way to tell them apart from the others is they are torsion bar front ends with out the 4x4. All the other 2x4 trucks had coil springs.

You truck sounds like the VHO (Very High Output) trucks. And its and LQ9 BTW.

One way to double check is look in the glove box door at the RPO sticker it'll list the RPO codes should list "LQ9" on it.
 

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VHo's are common in Texas. I guess they needed a truck with a little umph. VHO's were 1/2 tons with a LQ9. They also used a 1/2 ton rear end. V-Max's have a 3/4 ton style rear end and are on 4x4 frames. V-Max's are set up as a heavy-duty tow option in a 1/2 ton chassis. I own a 06 V-Max as a daily driver, and wouldn't think twice about droping anything on the back of it to tow.
 

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It's an LQ9

Thanks for the info guys! Torsion bars in front, 1/2 ton rear end & (drum roll), LQ9 marking in the glove box. That just makes my day! And explains why it runs as hard as it does. Now if I just had another one to stick into the five-seven. :happy0030:
 

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Thanks for the info guys! Torsion bars in front, 1/2 ton rear end & (drum roll), LQ9 marking in the glove box. That just makes my day! And explains why it runs as hard as it does. Now if I just had another one to stick into the five-seven. :happy0030:
get a tune and run 93 gas and you'll see/feel a BIG difference.
 

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How do you tune one?

get a tune and run 93 gas and you'll see/feel a BIG difference.
Can someone define a "tune" on one of these? Is it the reburning the chip that I have heard about? What all do you need to do it? A Laptop & a computer program of some kind? :confused:
 

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Can someone define a "tune" on one of these? Is it the reburning the chip that I have heard about? What all do you need to do it? A Laptop & a computer program of some kind? :confused:
A "Tune" is re-flashing the PCM (computer) with performance based perimeters vs the stock ones that are for everyday use.

This is done a couple of ways.
One is with a hand held tuner that removes the original tune and installes a custom one these are the Hypertech's etc. Another way is using a program such as EFIlive or HPtuners. It as an interface that you set what you want then it re-flashes the PCM.

The old "chipping" is used when the early ECM's actually required physical removal of the PROM to make any performance changes. So now of days its called "Tuning" the cars.


I wouldn't recommend HPtuners or EFIlive to anyone unless you know what you are doing! You can ruin a motor pretty quick if you mess with the fuel trims to much.
 

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Got the cart ahead of the horse

A "Tune" is re-flashing the PCM (computer) with performance based perimeters vs the stock ones that are for everyday use.

This is done a couple of ways.
One is with a hand held tuner that removes the original tune and installes a custom one these are the Hypertech's etc. Another way is using a program such as EFIlive or HPtuners. It as an interface that you set what you want then it re-flashes the PCM.

The old "chipping" is used when the early ECM's actually required physical removal of the PROM to make any performance changes. So now of days its called "Tuning" the cars.


I wouldn't recommend HPtuners or EFIlive to anyone unless you know what you are doing! You can ruin a motor pretty quick if you mess with the fuel trims to much.
Judging from what I have read elsewhere & you said here then I suspect that I would be better off leaving this 6.0 LQ9 alone. It is a stock 2004 that I have less than 30k on & still runs pretty remarkable to an old school small block guy like me. You had mentioned the tune & 93 octane in an earlier post. I learned a lot about the computerized end of it from you & doing some digging around on other sites. For now I think that I'll move on with trying to find an LS for the '57 & then worry about it. No sense in getting the cart ahead of the horse.
 

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BO185, do LQ9s have a different id letter in the VIN than an LQ4? Or are all 6.0s the same on that?
Yes it does! U is an LQ4 and N is a LQ9, look at the 8th character in the VIN.

Or look in the Glove box fro the RPO code. Really only way to know is look as the pistons, if unsure.
 

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Judging from what I have read elsewhere & you said here then I suspect that I would be better off leaving this 6.0 LQ9 alone. It is a stock 2004 that I have less than 30k on & still runs pretty remarkable to an old school small block guy like me. You had mentioned the tune & 93 octane in an earlier post. I learned a lot about the computerized end of it from you & doing some digging around on other sites. For now I think that I'll move on with trying to find an LS for the '57 & then worry about it. No sense in getting the cart ahead of the horse.
Running 93 in it will make more power. But you have to run a couple of tanks of more if you have run 87 as the PCM will have to relearn better gas. But it is little more power!


But the Achilles heel of these trucks is the 4l60/65/70's. The more power you make the shorter they last.
 
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