cole4.6

this might be a ballpark number for many reasons, but i currently have a 2004 Mustang GT completely stock other than a CAI. i am planning to put on the following: 73mm BBk TB intake, ford performance intake manifold, stage 2 comp cams, BBK ceramic headers, BBK catless X pipe,

Buck Sergeant

cole4.6, after you follow through with your outlined upgrade/performance mods, you will have one heck of a cool ride. To answer your question, with the many mods you are planning, only a before and after DYNO pull will answer your question. Get a pull now, and then a pull as you make your modifications. In this manner there will be no questions as to how much of a HP gain each upgrade makes. Make your last pull AFTER all your modifications have been made with your current exhaust. Then make the final pull with the new, and very efficient, exhaust system to go with the headers. Header gain is only accurate, and fair, with the correct exhaust system to complement the headers. Let me know the results.

Z28KLR

Hope you mean longtube headers. Gains with short headers are negligible.

Figure as your car sits currently, probably 230 rwhp. With all that done (plus tuning) 280 to 290 maybe.

WJL

Gears are your biggest bang, i would add a set of 3:73's maybe even 4:10's

WhiteFoxGT

question, why would you change the intake manifold? is yours bad? simply getting a new one because its a "ford performance" will net you literally 0 hp and simply make your wallet lighter.