wanting to get close to 400 hp.

I have a bone stock ATK remanufactured 318 155 stock hp. 8.6:1 compression. I have removed all smog parts, added headers, dual exhaust, 4 barrel intake and fitech fuel injection system good for up to 400 hp. would an edelbrock top end kit get me anywhere close or is there an easier or cheaper way? im realistic and am only shooting for 400, anything over 300 would be great.