i am looking to get a smaller pulley and headers with 3 inch down pipe and im going to completely get rid of the cat. i wanna know what you guys would recommend for pulley size if i am going to keep stock valve train. i can run 91 octain but would like to keep running 87. also my first time modding a car with fuel injection so i am new to reprogramming the pcm. any help on modding this car would be great thanks again.