I have a 2006 trailblazer that has a 4.2 i6 that I am swapping to a 5.3. So my question is on the ECM can I use the factory ECM with the new motor? Accordingly to GM they are the same part number. My guess is the software will be different or can this be corrected with the use of a new tune? Or how do I get new software on there?

Thanks in advance. Please let me know if this thread is in the wrong spot!