so i have this guy that wants to run against my truck and hes got a single cab short bed srt10. the guy says its stock to his knowledge other than the exhaust he put on it. he also had it put on dyno and says its putting down about 500hp. now i could see 500hp at the fly wheel and maybe 450rwhp but not 500 stock with a exhaust. does anyone know what these truck put out stock?