Dealer reporting different E67 part number used for 2009 Colorado V8 vs 2010-2012 model. ECM service part numbers 12636659 vs 12678513, respectively. Does anybody know what the difference is? I know for the 6L80E trans (in the Escalade), this was a big controller change year, so I don't know if it was a communication protocol, or the difference of VVT addition? I "thought" most all E67's were the same, but maybe not? Hardware or firmware difference?

I'm looking to get a spare E67 before I start tuning, but in the long run would like to eventually upgrade to a 6.2L, and wanting to actuate the stock 6.2L VVT mechanism.

Also, is there a lower cost path to acquire a used one and simply reflash it? I do have access to dealership level MDI and TIS web subscription to do so. OK to obtain used one, but need to keep same model year? Same engine?

Thanks, sorry for low level questions.