How to get a supercharged grand prix gtp to 300 horses?

What would be the most cost effective way to give a 240 horse, v-6 gtp an extra 60 horses to make 300? oh, and if it was done, what do you thing would be the car's 0-60 time? it is 6.6 stock, weighing 3450lbs with 240 hp and about 260 ft lbs of torque. thanks!