how can i get 400hp out of a 318?

Mopar to ya said
Going to have to bore and stroke it. I have the cam, intake, headers, carb, etc... and I estimate maybe 300 hp. That is probably optimistic.

jimjimjimmy said
4 inch stroker crank and 308 heads bowl work and a solid voodoo cam and poof 400 or close

Stroking an engine isn't always the best way to go, IMO the 360 already has too much stroke.... (great truck engine)

A 318 is basically a small bore 340, all you need to do is bump the compression, balance her and let her breath. 318s can be very formidable especially high winding ones.

Or keep the compression lower, balance her and force her to breath with a bottle/turbo/super charger