I have searched, and read a lot about both ECM's but nothing to sway me either way. I am planning to buy a GTO and curious if sticking with the LS1B (I have a 02 2500 with a 8.1) is worth narrowing my car search to the 04, or if the E40 is the way to go and not look at the 04's. The car will be a long term project that will eventually be turbo charged, as will the truck. I have read the DBW can be problematic with large amounts of boost which the GTO may see, but the 8.1 which is DBW will not likely see more than 8-10 lbs if that. Any real reason to give much weight to the ECM when looking for my next car? If I stick with the LS1B I will likely buy a RoadRunner. I am just getting off of the steeper part of the learning curve of EFI Live and starting to have some fun with the 8.1. The forum has been very helpful along with all of the fantastic tutorials thanks for those.