I have a 2018 Sierra with the 6.2L/8 speed transmission and would like to get an extra T87A TCM so I can swap out the original and keep it unchanged. I do not want to have it unlocked for tuning at this time but I am trying to determine which ones will work with my truck. There seems to be a large # of different codes on them and not a lot of info on what they mean. I'm sure I will have to get it programmed for my VIN but I should not have an issue with that. I just don't want to spend money on one and then have it turn out to not work with my truck. Any info would be appreciated.