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6.0 swap into 2004 Avalanche. Worth it?

Just4Kixx

Full Member
Joined
Jun 19, 2013
Messages
135
Location
Nova Scotia, Canada
Hey all, been a while since I've posted. I still had Old Blue, the ol' 2004 Avalanche, but this past spring it developed serious frame & body cancer and it was time to let it go. I ended up replacing it with a nearly identical 2004 Avalanche I call Pinky. Pinky is in much better shape than Old Blue, but for some reason doesn't seem to have the same power while towing. They both had 5.3's with 3.73's and 33" tires but for some reason Pinky can't haul a trailer quite as well as Old Blue.

I realize I could probably search through decades of old posts and find what I need, and normally wouldn't mind doing that, but my computer has pooped the bed and I'm stuck temporarily using this 8 year old POS that hardly works (I'm using Edge, for God's sake!!!)

I've now got the opportunity to buy a rusty 2003 Escalade for around $1k. It has the LQ9 in it, of course. The truck has about 335k km (200k miles) but is said to run very well. It is not drivable because the brake lines have rotted off. I'm seriously considering buying it, yanking the engine out, selling the rest for scrap, freshening the 6.0, and dropping it into the Avalanche. As I understand it, it should pretty much be a drop-in affair with some computer reprogramming required. Is this correct? Would using the Escalade's computer and tuning the antitheft out be better than using the Avalanche's computer and tuning it for the 6.0?

I'm thinking the 6.0's 55 horse and 50 ft-lb increase in power over the LM7 should make quite a difference in towing...

Any answers would be appreciated, thanks. I'm going to put this computer down before I throw it at the wall.
 
Can you at least connect a battery to it and start it.
 
Ya can't assume it runs OK. If it starts and goes into gear it maybe worth  a thousand.

There is a reason why people paid 15,000 dollars more for a ext, they have very strong drivetrains compared a AV.

How's the interior it may be a good parts truck.
 
Sounds like your 'new' truck likely just has a partially plugged converter. Installing new convertors would be much cheaper than an engine swap..
 
How did you determine that Rodney :E: :E: :E:
 
Yes, you could just drop the 6.0 in with some computer tuning.  You could either use your current computer or the one from the Escalade.

I am rather happy with the 460 hp 6.0 crate motor I put in Ol' Yellar 3 years ago.
 
MS03 2500 said:
How did you determine that Rodney :E: :E: :E:

Well.. When comparing two vehicles with same setup and one runs like a dog compared to the other it generally is something simple like a partially plugged converter. It is something that should at least be looked at. It is one item that doesn't necessarily throw a code but will greatly reduce the power output. If not looked at and found to be OK it would suck to spend the time and money to install a 6.0 and end up with it being just as doggy to find out it was just plugged convertors.

 
When I post an answer I look at their previous posts to see if they are a novice or someone who knows a bit about cars. He an Auto Technician so I'm thinking he has done some testing with it.
 
There is no plugged converter. Not towing a trailer it holds its own, but when towing it seems a bit underpowered. And we're not even talking a huge trailer. My 12X6 single axle utility trailer with my side by side on it, so maybe 2500 pounds. Even my husband commented on how gutless it felt last weekend when I was towing the side by side, and now this opportunity to buy the Escalade has come up. It's almost like a Godsend, because he isn't usually one to want to spend money.

I'm more interested in an upgrade than a repair. I simply want the truck to be able to hold its own compared to more modern trucks. Being a "bigger is better" kind of guy I am always for dropping a bigger engine in, I just want to verify that there is enough improvement to warrant the swap. I have my own garage with a hoist and full complement of tools (including torches), and am more than capable of doing the swap. I just want to make sure the 0.7 litres will make the difference I'm hoping. I'm actually thinking I could probably pull this swap off for next to nothing, because I could probably part the Escalade and make most of the purchase price back, plus once the swap is done I could probably get a few hundred for my 100k mile LM7.

The main thing, as I said, is that I want to not embarrass myself compared to newer trucks. I've even briefly considered trading my Mustang in on a new truck but it's almost paid for and I want to keep it that way. That and I don't want to drive a $50k+ truck in the woods like I do with the Avalanche.
 
Just4Kixx said:
The main thing, as I said, is that I want to not embarrass myself compared to newer trucks.

With my ATK 6.0, supercharger, and other mods I embarrassed a Shelby GT500 Mustang on the dragstrip earlier this year.  >:D
 
Much better high compression motor, stronger tranny 4l65e and rear diff on the escalade.

It's a little more than just .7 liters. If anyone drove a escalade and avalanche of the same year you will notice the difference. Escalades are road rockets. I say go for it if it runs grab the drivetrain if the interior is OK sell it and scrap the rest.
 
DO they have the same tire size?
Same rear end ratio?
 
ygmn said:
DO they have the same tire size?
Same rear end ratio?

Both are 3.73, the 33? tires & 18? aftermarket wheels on Pinky we?re actually taken off Old Blue before I sold it. Old Blue was a Z71 truck, Pinky is not but has the G80 locking diff. Old Blue was stock suspension with a 4? body lift, Pinky has a 3? suspension lift.

Think it?s gonna happen. Gonna look at the Escalade on my way to visit my husband?s parents on Saturday, and if I make a deal I?ll stop in and pick it up on Sunday on the way back.

I know some Escalades have the 14 bolt semi-floating rear end, am I correct in assuming this 2003 doesn?t? Also, do Escalades usually have 3.73?s, 4.11?s, or something foolish like 3.55? I know the SPID label will reveal all but just wondering...
 
I believe the 07 escalades came with the hybrid axle 14 bolt 9.5 inch ring gear semi-floater with 6 bolt axle.
They only came as low as 3.73 because of the 6speed trans 6l90e

I can't look it up right now but I'll check later today
 
The rpo code is AXN

http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=126217.0
 
Just4Kixx said:
I know some Escalades have the 14 bolt semi-floating rear end, am I correct in assuming this 2003 doesn?t? Also, do Escalades usually have 3.73?s, 4.11?s, or something foolish like 3.55? I know the SPID label will reveal all but just wondering...

All first generation EXT's came with the LQ9, 4L65 transmission, single speed full time AWD transfer case and 3:73 gearing in both front and back diffs.

The RPO code for the engine is: LQ9 Engine Gas, 8 CYC, 6.0L, MFI, Iron, GM, HO

The RPO code for the transmission is: M32 Transmission Auto 4-Speed Hydra-Matic Drive, 4L65-E Electronic, HD

The RPO code for my rear diff is:  GT4 Axle Rear 3.73 Ratio (DUP With 5 x 1)

The RPO code for the transfer case is: NR3 Transfer Case ? All Wheel Drive (AWD), Open Differential, Single Speed

There does not seem to be an RPO on my glove box door for the front diff.

As an aside, there is a post in this forum where a member had converted his 4X4 Avalanche to the AWD set up. either from a GMC or Escalade, I can't remember.

If I remember right, he had to get the front diff and the transfer case to be able to make the swap, at the very least.

Remember, the AWD front diff is an open diff and is fully engaged at all times.

You can not turn the thing off like a 4WD front diff.

You did not say you were considering this route, but I thought I would toss it out there to keep the waters stirred up.

(y).
 
EXT4ME said:
All first generation EXT's came with the LQ9, 4L65 transmission, single speed full time AWD transfer case and 3:73 gearing in both front and back diffs.

The RPO code for the engine is: LQ9 Engine Gas, 8 CYC, 6.0L, MFI, Iron, GM, HO

The RPO code for the transmission is: M32 Transmission Auto 4-Speed Hydra-Matic Drive, 4L65-E Electronic, HD

The RPO code for my rear diff is:  GT4 Axle Rear 3.73 Ratio (DUP With 5 x 1)

The RPO code for the transfer case is: NR3 Transfer Case ? All Wheel Drive (AWD), Open Differential, Single Speed

There does not seem to be an RPO on my glove box door for the front diff.

As an aside, there is a post in this forum where a member had converted his 4X4 Avalanche to the AWD set up. either from a GMC or Escalade, I can't remember.

If I remember right, he had to get the front diff and the transfer case to be able to make the swap, at the very least.

Remember, the AWD front diff is an open diff and is fully engaged at all times.

You can not turn the thing off like a 4WD front diff.

You did not say you were considering this route, but I thought I would toss it out there to keep the waters stirred up.

(y).

Thanks for the info. I off-road my Avalanche (and haven't decided whether I'm going to install the Fisher plow I still have from Old Blue), so I won't be doing the AWD swap. For now I'm just gonna stick with the 4L60E, but I might rebuild the 65 and install it at a later date with the 246 transfer case
 
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