2012 Chevy Express 4.8 to 6.0 swap

[FDLecuyer]

Hi everyone,

I have a customer with a 2012 Chevy Express 2500, he installed a 6.0l in the van to replace the 4.8l. Everything work fine no check engine light, no DTC. But he still runs the 4.8l PCM and tune. He kept the original transmission 6L90E but with the new engine she is now shifting harder but was working just fine before. I believe the added torque of the 6.0l is the reason why. Since some Express came from the factory with the 6.0l can I just flash the PCM/TCM with a stock tune file from a 6.0l equiped Express that I found in the tune repository and expect everything to work fine? I should add, everything is bone stock.

Thank!!

[5FDP]

No, HP Tuners can't flash all 8 segments that are required for something like that. You'd need to use a GM tool for something like that.

What you can do is find a 6.0 and use the compare feature to just copy over the difference into the 4.8 file instead. That way you aren't wasting money on credits and less risk of bricking the computer.

[FDLecuyer]

Thanks a lot, actually that is exacty what l wanted to know, if copying the difference between the stock 6.0l compare file over my 4.8l file would work. Flashing was not the term I should have used.

[hjtrbo]

Also, once you're done with all that, reset the trans adapts. It'll shift horrible to start with so just ease into it. If it's flaring or banging after a few drive cycles we'll need to take a look at what's going on. Make sure to log input shaft speed and output shaft speed as well. With all that said, you should be right though.