It might still be burnoff. Keep an eye on it and I'd change your oil 2 or 3 more times before you hit 2k miles. Dino oil for break in, dino oil till 1k, cheap synthetic till 1500 and then whatever you are going to use at 2k and then go to normal intervals. I'm kind of OCD about getting all the assembly lube, any little metal bits or any crap that got in there during assembly which should be minimal but still.
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.