I feel your pain with the slow 96-98 GT's. A good, quick mod for cheap would be to install some PI cams and a PI intake. With the PI cams you won't need to get new valve springs unlike other higher-lift cams. The trick with the cams is that you leave the cam gears on the chains and only remove the cams. That way you don"t have to reset timing or remove the front timing cover. Ford and Anderson Motorsports sells a cam-changing tool. There is plenty of info on intake install and it isn't difficult but TAKE UR TIME! Get a dyno tune after these mods and you will have a nice 225+ RWHP engine (on 87 octane) with a 5500 rpm redline that will work nicely with your 3.73's.
where can i buy some regular PI cams from for a good deal i found the pi intake for a 2003 mustang at rockauto.com for like 190 bucks but i didnt see any cams, also would it be wise to dyno tune it after this? wait you already answered that question, oops. would it be safe to say that a PI intake with PI cams after a good dyno tyne will net 15hp at the wheels or no?