Are you absolutely kidding me right now? Do you have any experiene with my particular vehicle or with the motor? The 4.6 is a very durable and powerful engine. To be up to par with a Z28?GT, the GT's of the same era have the same engine in them bro? Do you realize this? Just simply getting a SCT Tune in my car and a new rear gear and it will own any stock Z28/GT. From the lot my car cost $3500, its been retuned by my Uncle, and straight piped and I ran a ram air style intake. Its still basically stock, I know for a fact that it will beat a stock Mustang GT of the same era.