The WS6 Trans Am and SS Camaro are cars to fear, stock. I personally witnessed an SS Camaro run 13.1 with his 6-speed, and the car was showroom stock. The WS6 is essentially an identical car. Regular 98-02 T/As have 305hp LS1s, and the WS6 Performance Package ups output to 325. My friend just bought a 2002 SS SLP Camaro, and that car was advertised at 345hp due to I believe a modified SLP airbox and SLP exhaust, though I'm not certain.
The fact of the matter is, LT1 F-Bodies are pretty solid performers and with a little work can be tough to beat. LS1 F-Bodies are even more so, and with them being American V8 cars, I have no problem accepting getting beaten by a screaming WS6.