350-400 ponies for under 3 grand. This is very easy with the 351.
351 short block
351 heads with a GOOD port job(cheap)
Edelbrock aluminun heads, $1100 at summit and a CARB #
A good cam
Edelbrock or Trick flow intake
The tricky part is finding the wiring harness. I'm pretty sure Painless makes one, and I think ford still supplies one from the '95 cobra R. Pick up a summit racing catalog, they have the best prices on new stuff, but 350-400 is not that hard w/ a 351.