4L80E Clearance Issues?

[The Lost Texan]

@NickTransmissions

 

[The Lost Texan]

Nick
@NickTransmissions

Since you responded with some potential advice on this matter, would you care to elaborate and provide me your professional opinion? Based on my application.

Thank you,
Shane

 

[NickTransmissions]

Nick
@NickTransmissions

Since you responded with some potential advice on this matter, would you care to elaborate and provide me your professional opinion? Based on my application.

Thank you,
Shane

Hi Shane,

Are you looking for input on possibly doing a 6L80 or 6L90 swap for your truck?

 

[The Lost Texan]

I'm not Bextreme but if you can tell me how you plan on using the vehicle, engine power, frequency of high rpm use, frequency of heavy towing/hauling (if any), i can tell you what transmission, of the ones listed above, will meet your needs, given you're weighing ease of installation, fitment/integration as much as overall durability and strength handling...

Nick, this is the comment I am responding to.

I plan on driving it normal. Meaning I will be cruising it from town to town on county roads. In addition, I will be driving it at highway speeds (60-70mph) for the occasional weekend trip to cars shows, vacation, etc. I will NOT be drag racing, auto crossing, towing, etc. I want to build a reliable driver, with some decent power. I am a hotrod guy with multiple cars ranging from small block chevies to ford flatheads, all with 4 or 5 speed manuals. I don't know much about automatic trannys, like I do the muncie, saginaw and T5 transmissions. This will be my first LS/auto build. Finances are not a constraint, within reason. Just looking for advice, opinions on a combo set-up that will meet my needs, from knowledgeable people. The truck is completely blown apart with the frame powder coated on the hoist. I did install QA1's front crossmember/coilover system, along with the rack pinion steering- the idea was to make it more drivable. From here, I would like to make a decision on the tranny. I am almost 100% decided on the 6.2 motor, due to a friend having access to one. I also have another friend with a Stange ford 9" that will probably going into the truck. I am also asking for advice on gearing size, based on my application. I fully understand there are many variables to this, but just looking for opinions. As far as controllers, will the factory GM connect and cruise surffice? Or are there alternatives that you highly recommend? Are there controllers to avoid? Much Thanks, Nick.

 

[NickTransmissions]

Nick, this is the comment I am responding to.

I plan on driving it normal. Meaning I will be cruising it from town to town on county roads. In addition, I will be driving it at highway speeds (60-70mph) for the occasional weekend trip to cars shows, vacation, etc. I will NOT be drag racing, auto crossing, towing, etc. I want to build a reliable driver, with some decent power. I am a hotrod guy with multiple cars ranging from small block chevies to ford flatheads, all with 4 or 5 speed manuals. I don't know much about automatic trannys, like I do the muncie, saginaw and T5 transmissions. This will be my first LS/auto build. Finances are not a constraint, within reason. Just looking for advice, opinions on a combo set-up that will meet my needs, from knowledgeable people. The truck is completely blown apart with the frame powder coated on the hoist. I did install QA1's front crossmember/coilover system, along with the rack pinion steering- the idea was to make it more drivable. From here, I would like to make a decision on the tranny. I am almost 100% decided on the 6.2 motor, due to a friend having access to one. I also have another friend with a Stange ford 9" that will probably going into the truck. I am also asking for advice on gearing size, based on my application. I fully understand there are many variables to this, but just looking for opinions. As far as controllers, will the factory GM connect and cruise surffice? Or are there alternatives that you highly recommend? Are there controllers to avoid? Much Thanks, Nick.

So what type of transmission do you want?

If an automatic, what would you prefer to have? The choices could range from a TH350/400 to a 10L90 but prob lies somewhere in between...Given you're likely installing a 6.2, perhaps upgrading it's power output a bit and want overdrive, I'd recommend a 4L80E simply due to the relative simplicity, strength inherent in those units, support for tuning/controllers, etc relative to later 6-10 speeds and, dollar for dollar, much stronger than any 4L60-based transmission.

If you want to go with a manual, maybe an NV4500? I admit, I'm not nearly as knowledgeable about the manual transmissions given I very rarely work on them but others w/a lot more expertise will weigh in.

 

[The Lost Texan]

@NickTransmissions

The 6.2 engine will be the power plant....99.99% sure. Based on your opinion and a buddy of mine, I was really leaning toward a 4L80E. I know I want to stick with a 3 speed with overdrive (no 6-speed trannies, etc.) However, I just wanted to make sure this combination of engine/tranny is feasible. Meaning there are ECU's and harnessing kits available, to control, this particular marriage. I know nothing about the computer/harness side of these set-ups. Just wanted to make sure the compatibility, ease of installation, fitment issues are addressed, before moving forward. Is it safe to assume, if I acquire a used ECU/harness, there will be unnecessary wires and connectors, in addition, to control commands that will need to be deleted, etc. I didn't know if GM or any aftermarket companies offered a, for a lack of a better term "plug and play" kit, that could be built/mapped close to my application.

Thanks to everyone who responded. I appreciate it.

 

[Bextreme04]

@NickTransmissions

The 6.2 engine will be the power plant....99.99% sure. Based on your opinion and a buddy of mine, I was really leaning toward a 4L80E. I know I want to stick with a 3 speed with overdrive (no 6-speed trannies, etc.) However, I just wanted to make sure this combination of engine/tranny is feasible. Meaning there are ECU's and harnessing kits available, to control, this particular marriage. I know nothing about the computer/harness side of these set-ups. Just wanted to make sure the compatibility, ease of installation, fitment issues are addressed, before moving forward. Is it safe to assume, if I acquire a used ECU/harness, there will be unnecessary wires and connectors, in addition, to control commands that will need to be deleted, etc. I didn't know if GM or any aftermarket companies offered a, for a lack of a better term "plug and play" kit, that could be built/mapped close to my application.

Thanks to everyone who responded. I appreciate it.

If you have the coin for a connect and cruise kit... it will come with literally everything you need. There are multiple kits available... but none support a 4L80. Your options will be 4l60/4l65/4l70/4l75 or 6l80/6l90/8l90/10l90.

There are factory ECU's that do support running a Gen IV LS with a 4L80, they were used for running the 2500/3500 trucks with rectangle port LS3 heads and intake on an Iron Gen IV 6.0 block. The SUV packages that ran LS3 truck variants all used 4L70 or 6L80's. I currently have an L9H and 6L80 in my suburban and it works great. The burb weighs 7400lbs and I tow a 6400lb travel trailer at 70mph on the freeway with no issues. 33" tires and 4.10 gears in a 10 bolt and it has 240k miles on it now.

My buddy has a chevrolet connect and cruise kit in his 73 Nova. Its an LT4/8L90 combo he ordered from Jegs during covid. He hasn't had any issues with it. They come with a 2 year/24 month warranty... which is nice.

You can see all the available options here: https://www.chevrolet.com/performance-parts/connect-cruise-powertrain-systems

 

[NickTransmissions]

@NickTransmissions

I know I want to stick with a 3 speed with overdrive (no 6-speed trannies, etc.)

That sounds like you're leaning towards a TH400 with a gear vendors overdrive unit bolted onto the back of it. The 4L80E would serve both functions but the former would be purely mechanical with (as far as I know) no PCM/ECM/Electronic control..You'd just have the detent solenoid in the transmission and the electronics on-board the GV unit which are programmed from the factory...You can review their page here.

I would also suggest you begin to familiarize yourself with the various command and control options associated with doing this swap...You can't keep saying to yourself (and others), "I don't know anything about these ECUs and Computers, etc". Not knowing anything about them isn't getting you any close to making the right decision for you and your vehicle.

Here's your two primary options to consider if pursuing a 4L80E:
- Factory PCM/Wiring Harness/Segment program swap from the relevant year/vintage of the 4L80E you end up going with (for example: 1999-2013 4L80E - grab a PCM/Harness combo from that year range)
- Aftermarket Controller and Harness all-in-one solution (TCI, US Shift, MSD, etc)

The factory PCM / harness option would give you the flexibility to integrate customized tuning for your engine and trans via HP Tuners, EFI Live or other like-kind software however the stand alone controllers are pretty much plug-and-play and some can be tuned to match your particular vehicle, application, preferences, etc...

 

[Bextreme04]

If you can pull the 6.2 apart when you get it, you could convert the engine to Gen III specs with a 24x reluctor and 1x cam gear. Then you could run a factory 04-07 P59 ECU(blue/green) and have someone make you a swap harness for fairly cheap. The other factory option would be finding a stock truck in a junkyard with Gen IV 6.0/4L80 combo and buy the harness and ECU. That might actually be harder, since most junkyards are going to pull the whole drivetrain including harness/ecu if they are in decent shape.

 

[Bextreme04]

The aftermarket solutions are going to be tough because the stock Gen IV ECU doesn't output the right stuff for most of those controllers to work right. Someone probably makes an easy solution, but I don't know who that would be.