MUSTANG AND THUNDERBIRD?
Check out supersixmotorsports(d0t)com. They do some insane stiff with Ford sixers. They offer stage III heads, porting and polishing work, and even a custom sheet metal intake manifold! Past that, think Supercoupe. The Eaton blower will bolt right onto your TBird and can be gotten cheap! Fairly easy install too. For some serious power, look for a Procharger P-1SC kit. Awesome supercharger! That is what I use to turn 820hp out of a streetable Mustang with a 5.4L D.S.S. block! As far as a V8 swap, DON'T! You will need to get a new K-member (if going 4.6L, complete engine, computer, engine bay harnesses, fender harnesses, interior/dash harnesses, chassis harness, etc. You will even have to change over to a Hydroboost brake system, asnthe vac. system will not clear the modular V8 engine. I know, I have done this! DO NOT ATTEMPT!