Anything you can do to reduce drag and increase hp will add to the top speed. Top speed occurs when your max hp and wind loading match. Choosing the correct gear ratio helps to match them up. Wind loading increases with the square of the speed. Meaning you need 4X hp for 2X speed. But there are supporting mods you should consider for your safety. The correct speed rated tires and a drive shaft which will hold together at the higher RPMs comes to mind first.
2008 manual GT with deluxe trim, Edelbrock e-force, FRPP GTB Mufflers. 3.73 gears, Coast Ultralight Drive-shaft. 18" OEM Polished Bullitts, Webelectric Sequentials, XM built into the Shaker 500. Alarm and Escort RedLine.