You can get up to about 340 - 350 I reckon with ford 4.6lr mod kits from the states. Pullies, cams, throttles etc but like Keith says the s/c is the most cost per bhp effective. You can't do anything like turbos as the room is not there and you would have trouble with the heat. Again like Keith said induction is not worth the effort as it looks marginal at best.
If you have the money and serious about mod'ing it up e-mail me and I will put you in touch with some people that race mustangs, at a price they will sort your engine out with a few bits and bobs.
