Colorado e67 v8 swap question

[Hhh217]

Hey
I have a 2012 Colorado 4 cylinder that I am putting a 6.2 in. The factory ecm is a 12636659. According so current performances web site the 12636659 can?t be flashed with v8 software but the updated version of that ecm is 12678512 and capable of running the I4 and V8. Just for the hell of it since the ecm wouldn?t be any good to me if it can?t run my V8 I used SPS and flashed it using a 2012 factory V8 vin number. The flash completed but when I read the file out with hp tuners the ecm serial number is symbols instead of numbers. Do you know if I have to find the newer version of the ecm (12678512)or the one I have will work with a corrupt ecm serial number?