Hello Gregg,
Southern automotive builds a 390 pushed to 406 with 430 HP for around $6,000. a good deal for a turn key drop in FE motor. There have been articles in different magazines about this being the bargain Cobra motor that still gives the appearance of the 427.
Check it out at:
http://www.cobracountry.com/southern/home.html
You almost can't build it yourself for that kind of money and you get the integrity of the Southern Automotive folks behind your motor.
Tony R.