I can only tell you what Ive read over on svtperformance. I have read that the 03/04's have boost restricted for the first few key cycles. I cannot confirm because mine had 200 miles on it when purchased.
However many miles it takes you to get to your local drag strip!
I actually drove mine from NJ to NC and back the week after I bought it. Once I got home I went straight to the track! I think the break in period is supposed to be 1000 miles of city driving....driving at different speeds...
I dont think it really matters....although......
WHAT ABOUT THE CLUTCH? When you get a new clutch you are supposed to put 500 miles on it of city driving before driving it hard. I would think the same would be break in period would be needed for a new car.
Talk about a break in period, I have heard that the cobra doesn't really wake up until around 10,000 miles. A number of owners have told me that. They felt a difference in performance after that.
I've heard that too and I think its a load of crap.
Judging by the dynos I have had there were no unexpected jumps in hp from the mods I had done three years ago at 2000 miles vs. the mods now at 11,000 miles and I raced it every week weather permitting since June 02
but i would have to believe that the clutch would need the 500 mile city driving break in just like any other clutch.