I currently have the physical supporting mods just need to know if i can write over my tune. Both systems (mine and the one I want) use the 0411 but the service number (I guess is what it’s called) is different. Only difference is the flex stuff. From all the research I’ve done I’m thinking I can. Just going to cost more credits. I would pick this option first if possible. My other option is take a physical module I have and swap them under the hood, then read it, license it and start over. Not sure which one is more costly. The only hiccup with doing this is the module I have I specifically pulled from an 02 Tahoe with all the flex stuff, (stainless fuel tube between fuel rails, e85 sticker on tank door, etc...) but the service number is 12216121 instead of 12216125, which everyone says to use. The 6121 service number is almost nonexistent on net. I only found one thread that talked about it. But nothing to do with what I’m doing.