How fast have you gone with stock headers?
 

Since header upgrades on mildly modded mustangs have been a topic of late, I am wondering what kind of times people have attained w/ the stock headers?

Okay the first answer is i have seen low 10's :) but those were stock headers mounted upside down with twin turbos on them. In the intrest of giving you the answer that you are looking for though I have built several mustangs that ran high 12's all day long NA with the "stock" motor. What was changed on them was subframe connectors/pulleys/K&N/silencer removed/Gears 4.10's/slicks/minor weight reduction/mild porting of the head mainly grinding out the thermactor bump/timing/offroad h and not caring whether or not your T-5 lives. my opinion is yes the factory ones are little and pinched in places but they are not really the bottle neck they are made out to be.

I totaly agree. Well said.

Right on Brother! :D