It Can talk with the BCM if you re wire for it. The trans module is a different story.LBZ ECM will have trouble talking to the BCM and TCM as they are J1939 while the LBZ GMLAM
So, either keep the LLY ECM and FICM or swap out all of the computers and harness/repin
Also the reluctor wheel on the crank has 1 extra tooth on the LBZ vs the LLY.