6.0 w 6L90E
Thread Starter
Teching In
Joined: Nov 2014
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6.0 w 6L90E So I bought a 2011 6.0 w 6L90E transmission from a Silverado 2500 4X4 for my 72 Chevelle. I know the Tunnel has to be cut out and the tail shaft changed to the 2WD version. But does the computer and wire harness have to be altered/reprogrammed for this swap? Im trying to figure out everything im going to need to prepare for. Any help, tips, suggestions and knowledge would be great...
TECH Resident
Joined: Mar 2012
Posts: 821
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From: Elkridge MD
If you pulled the trans and motor from the same vehicle, you shouldn't have to reprogram for that.
However, if you did not get the body control module and the key, you will need to have the VATS removed (vehicle anti-theft system)
However, if you did not get the body control module and the key, you will need to have the VATS removed (vehicle anti-theft system)
Thread Starter
Teching In
Joined: Nov 2014
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Vats How do I go about having the vats removed?
TECH Resident
Joined: Mar 2012
Posts: 821
Likes: 4
From: Elkridge MD
Most people send the computer out to a programmer. You can find local places to do this as well. You can expect to pay something like $75 for that service, although if you want more power, you can also have the computer tuned to wake up the engine a little bit, and also account for headers, a cam, intake, CAI, etc. I used PCM Performance, and paid $300 to have both my ECM and TCM tuned (You may not have a TCM with that transmission though, I am unfamiliar with it) They told me their tune was good for about 30 extra hp, not counting whatever horsepower i freed up by putting long tube headers on.
There is also a much cheaper way to delete the VATS yourself, by using a resistor on one of the wires coming out of the computer, but I don't know how that is done. Someone else with more experience will have to chime in
There is also a much cheaper way to delete the VATS yourself, by using a resistor on one of the wires coming out of the computer, but I don't know how that is done. Someone else with more experience will have to chime in
One item to consider is the significant dept of that trans oil pan. I grafted the front of the 6L90 pan to a 6L80 pan. Also, what are you going to do for steering linkage? Floor or column shift? I'm still looking at options, but leaning towards the Kugel Komponents setup.
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Verdad Gallardo I think it's a good idea to purchase a subscription alldatadiy.com for the vehicle your engine/trans/harness, etc came out of as well. They have good pin out diagrams for almost everything you could want. It's pretty cheap as well. Really helped me figure out my G8 harness.
I have the same set up and found all I needed. If you cant find it pm me and I will did up the link?info Great combo to start with!! 
Teching In
Joined: Oct 2016
Posts: 23
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From: Ottawa, Ont. Canada
Sorry to bring up an old thread but did anything ever come of this? I am planning on putting the LY6 and 6l90e trans (out of an '08 Sierra 2500HD) into my '85 Cutlass. I want to get as much info as I can before I start everything.
I will be making my own engine mounts, and also modifying the truck pan so I can keep the VVT offered in the LY6. Along with the pan I will be modifying some f-body headers as well. As for the trans crossmember, I will also be making my own and altering the transmission tunnel to fit the beast of a transmission. I am still unsure on what to do with the Trans pan and also how to get the drivestaft to work (any tips on this would be appreciated).
The main thing I am unsure about is all the wiring and tuning. I bought the 2008 truck complete minus some body panels so I have the original harnesses, computers etc. I've looked on LT1Swap.com and noticed that he has pretty good instructions on what wires to remove or move around within the harness. What I'm mainly concerned about is that once I alter the harness will I need to get the ECM tuned even if I plan on running the engine stock minus headers? Also do I need to remove the TCM from the pan and get that tuned as well or will the tuning in the ECM control the TCM regardless?
As you might have figured out this is going to be a budget base swap. After unloading the rest of the parts I got off the truck the engine and transmission are essentially free and even made some money out of the deal. With that said ANY and ALL help would be appreciated, but if you have a more budget friendly way of things that you know works that would be even better.
I will be making my own engine mounts, and also modifying the truck pan so I can keep the VVT offered in the LY6. Along with the pan I will be modifying some f-body headers as well. As for the trans crossmember, I will also be making my own and altering the transmission tunnel to fit the beast of a transmission. I am still unsure on what to do with the Trans pan and also how to get the drivestaft to work (any tips on this would be appreciated).
The main thing I am unsure about is all the wiring and tuning. I bought the 2008 truck complete minus some body panels so I have the original harnesses, computers etc. I've looked on LT1Swap.com and noticed that he has pretty good instructions on what wires to remove or move around within the harness. What I'm mainly concerned about is that once I alter the harness will I need to get the ECM tuned even if I plan on running the engine stock minus headers? Also do I need to remove the TCM from the pan and get that tuned as well or will the tuning in the ECM control the TCM regardless?
As you might have figured out this is going to be a budget base swap. After unloading the rest of the parts I got off the truck the engine and transmission are essentially free and even made some money out of the deal. With that said ANY and ALL help would be appreciated, but if you have a more budget friendly way of things that you know works that would be even better.
On The Tree
Joined: Sep 2007
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The ECM will need flashed to remove vats first and foremost so the vehicle will even start. Then if you aren't using emissions you will need those codes along side other various codes removed that would pop up during a swap. The TCM doesn't need to be pulled and flashed unless you need or want gear ratio/tire size programmed in or tap shift functionality enabled.. Since the ECM & TCM are from the same vehicle you won't have to pull the TCM unless you want the aforementioned stuff programmed.
Teching In
Joined: Oct 2016
Posts: 23
Likes: 0
From: Ottawa, Ont. Canada
The ECM will need flashed to remove vats first and foremost so the vehicle will even start. Then if you aren't using emissions you will need those codes along side other various codes removed that would pop up during a swap. The TCM doesn't need to be pulled and flashed unless you need or want gear ratio/tire size programmed in or tap shift functionality enabled.. Since the ECM & TCM are from the same vehicle you won't have to pull the TCM unless you want the aforementioned stuff programmed.