700R4 to 4L80E in my 87 Chevy Blazer

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RanchWelder

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Some people have posted that it is possble to swap out my 700R4 and install a 4L80E using the L29 or 0411 ECM?

Own the L29.
Will it work or not?

The questions are:

1) Has anyone sucessfully used either ECM to control the transmission, without altering the OBD1?
2) Which ECM can be easily reprogrammed to remove the VATS and swap the gear ratio from 4:10 to 3:73? ..... 0411 or L29?
2) Which part number pigtail works foir this application for the 4L80E?

Summit has several listed and I'm not certain which one will work for my 1999 GNT400 4L80E.

Don't want to butcher the GMT400 harnes at either end.
Do not require a harness, because there's only 4 wires needed to the ECM and from the ECM, or at least that's what appears to be required, I'd like to know from somebody if there's more wires from the ECM to transmission...

Have the pin out diagrams for both ECM already.

Lastly:

Is there a forum member who is familliar with using tunerpro to turn off VATS and change gear ratio's and if so please tell me who you are so we can get this done ASAP?

Want firewood before it gets -40 here and my Blazer is easier to fix with this swap than my Mark VI Big Block bearings oil pump and that's if that is all that's wrong... my Blazer engine is new and mintish. I can cut and weld the driveshaft and make an extention for the front shaft.

Anyone who has the good on this, please speak up..

If I can use the L29, I need to know ASAP so I can buy piggies. If it is the 0411 I need, then same same.

If anyone has spare 0411 ECM, piggies, for either ECM if one or the other won't work, please email me so we can work something out.

You guys Rock!

*This post is also on GMT400.com
 
Last edited:

NickTransmissions

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Some people have posted that it is possible to swap out my 700R4 and install a 4L80E using the L29 or 0411 ECM?

Own the L29.
Will it work or not?

The questions are:

1) Has anyone sucessfully used either ECM to control the transmission, without altering the OBD1?
2) Which ECM can be easily reprogrammed to remove the VATS and swap the gear ratio from 4:10 to 3:73? ..... 0411 or L29?
2) Which part number pigtail works foir this application for the 4L80E?

Summit has several listed and I'm not certain which one will work for my 1999 GNT400 4L80E.

Don't want to butcher the GMT400 harness at either end.
Do not require a harness, because there's only 4 wires needed to the ECM and from the ECM, or at least that's what appears to be required, I'd like to know from somebody if there's more wires from the ECM to transmission...

Have the pin out diagrams for both ECM already.

Lastly:

Is there a forum member who is familiar with using tunerpro to turn off VATS and change gear ratio's and if so please tell me who you are so we can get this done ASAP?

Want firewood before it gets -40 here and my Blazer is easier to fix with this swap than my Mark VI Big Block bearings oil pump and that's if that is all that's wrong... my Blazer engine is new and mintish. I can cut and weld the driveshaft and make an extension for the front shaft.

Anyone who has the good on this, please speak up..

If I can use the L29, I need to know ASAP so I can buy piggies. If it is the 0411 I need, then same same.

If anyone has spare 0411 ECM, piggies, for either ECM if one or the other won't work, please email me so we can work something out.

You guys Rock!

*This post is also on GMT400.com
Call Summit, if you haven't already - their tech support should be able to guide you to the right ECM for what you're trying to do...There's also plenty of harness kits available as well...Also, check eBay if you haven't already - they sell VATS-free ECMs 0411 and L29....Vet the sellers thoroughly before you buy but I have seen a bunch on there.

You can also go to the junkyard, grab an ECM and full harness assembly from a 2500 or 3500 series truck then use HP Tuners (or have a knowledgable tuner in your area) to reprogram per your needs.
 

Hunter79764

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This is an option if you just need it working?
 

82BBC20

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Yes it can be done, I’m attaching a screenshot of an article I found on bangshift.com. I’m currently wiring my 4L80 in my 92 2500 Suburban to run with carburetor using info from this article.
 

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RanchWelder

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My only concern with the switch panel is it runs at full pressure, all the time.
Variable pressure is correct for street driving.

If the pump ever runs at full pressure, it will crack the case or blow the seals out on the highway.
I see TCI has a variable pressure control module, which can be installed and controlled on the fly.
But this mod requires the guts of the system be installed during rebuild.
I have heard stories of transmission shops installing full manual 4L80 on street rods and then asking for huge money when the over pressure kills the transmission, due to daily driving with full pressure mods.

If anyone has a quality control unit, in good working condition, I am vey interested in buying a known good unit or testing a new design.
My 4L80E does not have a VSS output reluctor wheel.
In 99 they put them in the transfer case. The 99 drops on the wrong side, so I cannot weld it to work on my 87' 10 bolt front axle.
This means I have to tear down the entire transmission and install the $100 Novak reluctor kit.

I'm tooling up for the rebuild of my first 4L80E. Anybody with old transmission mounts, tools or solid deals on rebuild kits, please PM me with details.

I'm stripping out the 1999 K2500 for the transmission and the 10.5" 14 bolt FF.

Anyone want the heated electric leather seats, GMT400 door panels or the transfer case, or 7.4L sensors or pigtails, let me know.

It is tan interior, zero rips tears or wear. The dash is mint too. Heater core, radiator, torsion bars, keys, front hubs, no rust here in Montana.
Doors, glass all very good silver paint, no damages. Every door hinge works flawlessly.
The truck was garaged for the first 57K. It has just over 100K now.

I cannot afford to rebuild the 7.4L so this beautiful truck is getting scrapped out. The harness is already cut.
Could fry an egg on my forehead.
 
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Ricko1966

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This is an option if you just need it working?
I did this method before I'd ever seen a writeup to get home from Columbia. This method and the cheap controllers both run full line pressure at all times.They only provide grounds to control the shift solenoids. I posted up last time people suggested this,what pump modifications are necessary to prevent transmission damage.
 

Ricko1966

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Ricko1966

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@RanchWelder lookie what I ran across. A whole write up on home made 4l80 controller using an 0411 ecm
 

RanchWelder

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Ricko1966 I have the 0411 pinout and the Blackbox ecu piggies already.
A great guy from IL sent me the 0411 to Black Box pin out diagram...

Just bought a Jake's stage 2 4L80E rebuild kit today.
Thankfully, I learned the input shaft on the 1999 is already damn near the strength of the 4340 $300 shaft: ... and I DON'T NEED IT...
Thank goodness there's still a few good guys and an honest assessment out there, if you scratch the right itch with good guys.
The stage 3 kit he sells is awsome. I had no idea ther 1999 had an incresed strength shaft, already. Saved me a bunch of cash for the new tools I require, to rebuild a few of these.

You guys are awsome!
 

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