back into cars,yay !

400HP is easy. http://www.popularhotrodding.com/enginemasters/articles/mopar/0667em_mopar_318_engine/viewall.html
that's just one way.

seriously though... i'd leave the 318 in her for now. get a used 360 somewhere. build that sucker up. then swap it in. you will get more HP for less money. it wont take much to hit 400HP with a 360. heck you could even put a stroker kit in the 360 and get close to 500.

it's all what you want to put into it, really.