how can i get 400hp out of a 318?

potentially cheap build here:

http://www.hotrod.com/howto/113_0304_318_small_block_build/

will end up being costly if you farm all your work out.

another option like mentioned is higher compression pistons and 360 heads.

I do also believe there was a 400 hp 318 with magnum heads but i don't have that build bookmarked.