The LS1 Firebirds, despite their poor sales, were among the fastest ever produced. Outfitted with the all-aluminum 5.7L V8 from the Corvette C5, and producing 305 hp (227 kW) at 5,200 rpm; 335 ft·lbf (454 N·m)

Top Speed 155 mph / 250 km/h (electronically limited) this was for 2001 and below.
2002 was raised to 165 mph (electronically limited). Power was also upped to 330 with Ram Air 350 HP. These were serious cars. The highest top speed on a Limited I ever read was 150 mph. That was on the Autobahn when they first came out.