Start with: Underdrive pulleys, rear end gears(i like 3.55's, 3.73s kinda kill highway mileage), and a full exhaust. On my 94 gt, i have summit headers, bbk prochamber x-pipe, and vortek cherry bombs. Its a killer exhaust, but i dont like the prochamber, id get the regular xpipe. I eliminated the cats, and the smog pump, good for a little extra power, for free. I also did away with the EGR, but noticed no real gain there. If your comfortable doing any tuning, i would advance the timing to about 11.5 degrees before top dead center, in other words, 1.5 degrees ahead of stock. My favorite way to time is with a vaccume gauge, and set it to max vaccume at idle with the spout disconnected. Next if you want more power, i would do a 65mm throttle body with a 70mm MAF and 24lb injectors through a good intake, such as the GT-40. Why stop there? Heads are the biggest way to make power from a 5.0 due to the stock heads being a little asthsmatic on the exhaust side. there are many good brands out there. SN95 5.0 mustangs dont like cams, they make for a poor idle and low vacume down low, if you plan a cam, you will need to have your computer tuned for it, but after all those modifications, it would be stupid not to get in re-flashed. hope this helps.