L83 to L86 Swap

[2015 High Miler]

Sorry to hiljack but I am Interested in this swap as well. I have a 2015 5.3 w 225,****** and climbing.  I see 2017 and 18 L86’s for sale with trans and transfer case for about $5-7000 quite often.  Can I swap the 8 speed or should I keep the 6 speed?  I have a few shops locally that can do the swap for me. 
 

thanks for the feedback. 
 

 

 

[Snowcamo]

Agreed any updates on the swap?

[cph60fixr]

So, I have been driving the truck now for a few weeks 500 miles with no issues.  I kept the 6l80e trans because I had just overhauled it.  And some people think the 6l is a better trans then the 8l.  What I cannot figure out is I went from a 5.3 w/mailordertuner to the 6.2 and I have no check engine light, no driveability issues, nothing.  It runs great.  Ask any questions, my ASE Master Tech cert expired in 2016.  And I am back into Contracting as a Aviation SME for the US Army at Ft. Campbell.

[Snowcamo]

So maybe a few ins and outs? Like exhaust or any wiring issues? Hows the power difference even with the 5.3 tune?

[CamGTP]

Just because it runs okay with no check engine lights doesn't mean it's "correct". It's just like when people did/do 5.3 to 6.0 swaps, the 5.3 calibration can run a 6.0 or 4.8 without even flinching but it's still not correct.

 

The engines share tons of parts and the computer is very good at making corrections on the fly to fueling but the entire airflow model and torque model is still wrong.

 

The airflow and torque model being right is what is important, these are torque based controllers. Everything is based on engine torque, transmission torque, axle torque etc etc. If things are wrong for a long enough period of time it will slowly cause wear to the engine and transmission. The adaptive learning can only do so much to make it seem like things are working correctly.

 

I've been tuning LS and LT engines for most of the past 10 years. They don't teach this stuff in the dealership and the ASE stuff gets you no where when it comes to this. If it was me I'd have it tuned to correct all this to hopefully save my bacon in the long run.

[cph60fixr]

Got it, I have never worked in a dealership.  Torque is everything!!  Agreed!  Time will tell if I have made mistakes.  The swap was absolutely plug and play.  GM did change the torque converter bolt pattern from 15-18!  I had to remove the trans and swap out the 6.2 flexplate with the one from the 5.3, that sucked as unexpected.   I am very happy with the new 6.2.  I am a transmission rebuilder in my play time.  Everything else I do on vehicles is just turning wrenches.  "no challenge".

[Tucker23]

On 1/23/2022 at 6:09 PM, cph60fixr said:

So, I have been driving the truck now for a few weeks 500 miles with no issues.  I kept the 6l80e trans because I had just overhauled it.  And some people think the 6l is a better trans then the 8l.  What I cannot figure out is I went from a 5.3 w/mailordertuner to the 6.2 and I have no check engine light, no driveability issues, nothing.  It runs great.  Ask any questions, my ASE Master Tech cert expired in 2016.  And I am back into Contracting as a Aviation SME for the US Army at Ft. Campbell.

What tuner did you buy?, i have a 2015  5.3 Silverado and am swapping it with a 2015 6.2 should I buy a new ecu that’s got the vin to the 6.2 and do that or just buy a tuner and try tuning my 5.3 to a 6.2 tune???

[CamGTP]

Have someone tune your truck for the swap.

[Homewrecker007]

X2 on above post.

[superdave160]

Chris, if you want a good dyno tune, I recommend Carma Performance in Nashville.  I have a 2017 Silverado with the 5.3L and 6L80 transmission.  I had a DOD delete, bigger cam installed, and L86 intake and throttle body installed in my truck.  I had a local shop here in Alabama tune it and it was a train wreck.  I took it to Carma Performance and the truck now drives like it should.

[MikeBMW]

I used SuperChips F5 FlashPaq from Holley to do my tune for a 91+ octane tune as well as reprogramming for tire size and DOD delete (though I could also do that with the AutoSync from BTDiesel)

https://www.holley.com/brands/superchips/products/tuners_and_programmers/handheld_tuners/superchips_f5_flashpaq/

https://www.btdieselworks.com/collections/autosync