Straight from Peter at GIAC USA:
Yes you can use a previously programmed ECU, BUT* you will need to "exchange the liscence to use in your vehicle which will be $200.00 plus shipping. you can't mobilizer defeat it, because it will trigger a security breach and lock the ecu. (this ensures no one else can copy/re-use your ecu flash which is why the flash is VIN specific.
Else/Or
Just call up your local performance shop, GIAC flash it for $450, or custom mapped tuning for the same price.:thumbup: personally love the custom flash, they flash your ecu about a dozen times, load test every time and give you a free flash. reliability. not even an issue.
Get it done the proper way, or don't do it at all!
my 0.02 cents.
Cheers:beer: and good luck