What hp gain could I see from installing a Cold Air Intake,Longtube headers,offroad h-pipe with a Custom Tune?

 

Well that depends on which intake/tune, which headers, is your car a manual or auto, what dyno you get it tuned on, what the temperature is, who tunes it, etc. Too many variables, it could be anywhere from 30-60hp in worse case or best case scenarios.

 

Depends on the motor too. To which are you referring.

 

I don't know the answer to that question. But, I know you'll smile more every time you drive it, that I can guarantee. I would recommend buying everything through one shop (Brenspeed, AM) any of the known good shops and you'll be very happy, plus they could answer your HP question too.

 

Its a 4.6, 2008 Mustang GT,I actually have OBX longtubes, KNN CAI, its an automatic, I got a Bama tune at AM,what could the highest hp be with those mods?

 

Well with obx and k&n I would say anywhere around 35-45 horsepower at the wheels but I can't be positive. I would worry less about numbers and more about the "seat-of-the-pants" dyno.