350hp is a pretty good, and reasonable goal to aim for.
That should be possible with a good cam, headers, intake manifold and a holley carb.
A stock bottom end (with updated bolts like ARP) should be able to handle that much power.
Try researching the intake manifolds, and headers through edelbrock
http://www.edelbrock.com/
Weiand manifolds (web address unknown)
And Holley
http://www.holley.com/
Plus comp cams
http://www.compcams.com/