L92 swap into ly6 hd truck

Kevin LeBlanc · February 24, 2022

I am new to this forum, first post, so please forgive my ignorance of etiquette. I have a 3500hd dually with an LY6 in it. I'm looking to increase torque for towing without getting drastic with the supporting mods required to do so. My main question is is swapping an L92 into my truck a pretty straight-forward affair? Will the ecm and tcm still function properly? If there is info on this swap already, and I haven't found it yet, please steer me in the right direction. Thanks in advance.

CamGTP · February 24, 2022

The L92 swap is simple as far and nuts and bolts go.

The difference comes with the compression ratio and the tuning. If you swapped in a 6.2 engine the 6.0 calibration would not be incorrect for running it properly. The L92 gets it's power from a more aggressive timing setup and premium grade fuel. Plus a bunch of other stuff in the calibration that would need updating on the 6.0 tune to make it run good all the time.

A stock 6.0 calibration running a 6.2 wouldn't give you all it could. The calibration is made soft on a 6.0 because it's a work horse that is designed to be beat on all day everyday and not break down. That is also why they run lower compression and can use 87 octane fuel. The 6.2 on a 6.0 calibration would have more power but that would be until the computer starts taking it right back out. The soft timing and higher compression on 87 octane would likely cause lots of spark knock and the sensors would yank a bunch of power away.

If you tuned the computer to run the 6.2 and ran at least 89 octane or 91+ octane then it would be okay and give you more power.

If it was me I'd just buy a mild camshaft, lifters, pushrods and valve springs for the 6.0 and get that tuned. Even with everything else stock on some mid grade fuel with the lower compression it should still pick up atleast 35-40hp and the same or more torque. This route would be cheaper if you did it labor portion yourself, it would be probably $1,000 in parts total give or take. A 6.2 around where I live is a lot more than $1,000.

Kevin LeBlanc · February 25, 2022

Thank you for the input. It is much appreciated. I will investigate that route instead. I've heard good things about the "Truck Norris" cam. Thanks again

David89GMC · February 27, 2022

Good information from CamGTP, the 6.0 is what we used to call "detuned". Just getting a hotter tune may be all you need. Keep in mind that the LY6 has variable valve timing, so you might look more closely at modifications for that.