The 2002 Corvette weighs roughly 3250 lbs and has about 350 HP. Corvettes have some big rear tires for traction as a stock item. The C5 model will do 0-60 in about 4.7 seconds according to a review at
http://consumerguideauto.howstuffworks.com/1997-to-2004-chevrolet-corvette-1.htm. The HP to weight ratio is 9.28:1.
Your coupe is probably 200 lb lighter, and if you ditch the stereo it will help in the weight area. The 3000 lb ready to race mark is what you want to weigh in at. You'll need subframes connectors and some good lower and upper control arms to plant the rear axle since Mustangs are notorious for poor traction. Some sticky tires will be a must have too. You’ll need 3.73 gears or better for the rear end to get some good acceleration.
Figure that the Corvette has 9.28 lbs per HP, you need 9.2 lbs per HP or lower . Given the weight advantage, you’ll probably need 285 -295 rear wheel HP. Remember that you lose about 15% power through the drivetrain, so the flywheel HP will be about 327-340 HP. With a stock block 302, that means some excellent heads (AFR’s or Trick Flow CNC) intake, cam and a mass air conversion plus a quality dyno tune. This will not be a cut corners, throw parts at it, kind of job. You will need the best quality workmanship and tuning skills to make this kind of HP consistently. The car will probably be less that daily driver friendly with a 302-306 in that state of tune. The torque curve will have moved up the RPM range that is out of the range of normal street driving.
How much will it cost? All of the figures are with DIY labor. If you aren’t a really good mechanic or don’t have the tools, this job is going to be prohibitively expensive. Heads are $1600-$1700 with all the rockers, pushrods gaskets and other parts. Intake is another $450-$550, the cam is probably going to be $250 or more for the custom grind you will need. Mass Air conversion is $150-$200, Big MAF - $170-$300 and throttle body $140-$225. Fuel pump - $85 -$100 and adjustable regulator - $70-$95. Gaskets, sensors and other small parts is another $300. Gears -$350, subframes – 200 installed, control arms $300 plus some sticky tires - $200.
This totals out to somewhere around $4500-$5000 by the time you top it off with a custom tune. Buying used parts may save some $$$. You need to be sure that they are in new condition or you will spend more money than new trying to get them that good.