[MJN]

Your dyno sheet looks about right for that motor. The Air/fuel ratio is pretty much spot on so don't go messing with fuel pressure. More timing will definitely help. With iron heads 12 -13 degrees base timing should be OK on 93 octane, with aluminum heads you can use a couple of degrees more. 2 or 3 degrees timing should pick up as much as 10ft lbs of torque and maybe 6 - 8HP.

Basically it looks like you have a well matched combination, if you change any one single thing you may not see much of a gain until you have changed everything. Going to 5/8" shotry headers may give you a few HP in the upper rpm's (5hp or so) but may lose you some bottom end torque. The FFR sidepipe and stock Mustang header set up can be replaced with a proper 4 into 4 for a larger gain in torque and HP. You should have a 65mm throttle body to work well with the Cobra intake and the mass air meter should be a minimum of 75mm, 80mm or larger would be better. That's about all you can do without getting inside the motor. You might see another 20HP with 4 into 4's , 65mm throttle body and larger MAF. If you want more HP with a HP to peak closer to 6000 rpm then consider a cam change but be prepared to lose that nice fat torque curve. To really wake up the motor at higher rpms a better flowing intake and probably better heads will be required along with a cam selected to work with them.

Building HP is an educational experience and education isn't cheap these days. Hey, it's only money, right? And besides that's part of the fun of owning one of these cars.