If he upgraded to a larger axle which he probly did given his bad luck with the other axles he would notice a small loss in power. Nextly his car is a vert which pretty much null and voids his benifit of being a cobra over gt on a stock level. Also those heavier rims and low profile tires arnt doing him any favors for performance and are also hurting his E/T's. As well you have a fresh motor vs his motor that has been worn down by 17 years of age. If you feel like he was making excuses he probly was. I doubt he was a bad driver your car was probly just faster. The way I see it you got a clean kill, plain and simple.