I have had good luck with mine (ceramic coated). Pacesetter headers are not the highest quality out there, but they look cool and there not a thousand dollars either!!
I have an 87' GN. Turbo buicks are amazingly powerful when there running right, however they have little issues like most cars. Mine has gone a 12.0 with the STOCK turbo!
I didn't see anything about the fuel system. Like any forced induction car, the fuel sys. is important. If u don't already have it, Get a good in-tank fuel pump(walbro 255). For $300 u could get a MAF translater/LS1 mass air sensor combo and ditch the stock mass air sensor. The GM 3.5" m.a.s...
Jeez! talk about having to spell it out. Good Job! As far as the final torque on the NUTS, Don't get fancy with it. ARP wants the bolts/studs "stretched" to a certain point. when guys torque them higher then recomended, They are stretching the bolts/studs higher than ARP recomends. More is not...
04' cobra, NICE! I'm not a mustang guy, but 03-04' cobra's are serious cars. I have an 87' Grand National and an 02' Z06. Last summer my 91' talon was just as fast as those cars and this summer i'm expecting it to be faster then both! My DSM is cool because I can actually afford parts for it...
It's not always fuel cut! My 91' talon was falling on it's face around half throttle and it was the THROTTLE POSITION SENSOR! Check for engine codes before u go spending money on parts u may not need.