Nice GTO. To get 300 you most likely did a ls6 intake or a Fast intake with a 90 mm tb and a Cold air intake. with a small tune well thats what i would do and still have it sound stock.
I need to get some sexy shots of my V. I hate all this rain i hope it hold off over the weekend so i can have my friend come over and shoot my car. Welcome and you have a very nice GTO