I've tried to research but haven't found anything in depth regarding 09-10 E38 compatibility w/6L80. Maybe I can get an answer to my particular circumstance. I've got a 09 Sierra, Originally E38, 5.3 LC9 (AFM) w/6L80. Currently has a 2010 4.8 w/VVT with the same 2009 6L80.
Question, Can I add (is it on the ecu already?) VVT to the original tune to not disturb any possible compatibility issues?
If I do have to use a stock 2010 tune in order to keep the VVT, are there any known compatibility issues between the 2010 ECM and 2009 TCM?