how can i get 400hp out of a 318?

400 HP today isn't the same as 400 hp back in 1970, LOL

You still could build a strong running 318 that can take on these "400 hp" new cars today. But yeah nasty cam, heads and gears in the 4 range is needed.

I stop reading those mag back in the 1990's, don't think they are much better today.