600 starts to be a limit with the stock internals on a 2v 4.6 unless your talking about the 4v Cobra motor. The rods and crank just will not take it.
You can acheive 600hp on a 302 but be prepared to break the block in half. So if you want a nice, reliable motor with that kind of power your going to spend about $4200 on a 331 DART shortblock, $1500 in heads/springs, $600 in the intake, $800 in TB/MAF/INJ, $330 cam, $200-$500 in rockers, $750 in headers/x/cat back, $2500+ for the blower. Plus all the little things.... $10,000+
Then you need to do the chassis so the car doesn't twist up...
Either way its gonna be expensive... Probably be cheaper to use a 4.6 cobra 4v engine because you don't have to start from scratch. It already has all foraged internals. Supercharger pullies, exhaust, cams, chip... basically bolt on stuff is what you are gonna need for the cobra motor.