Why even mess with a 302, 347, or 351?
If you're going to build a mustang do it right! Go with a 429 Cobra Jet with twin Paxton Superchargers.
Check it out @
http://www.cobraautomotive.com/images/paxlnk.jpg
this is the way to get real power, and real speed. Don't mess around with small blocks go with big blocks.
Andrew