Better Torque From A 318

Most people aren't gonna port their heads and even if they did no guarantee their gonna get great results. So your basically talking stock or pay someone else to do it.

If looking for decent power 300-425 hp stock 273/318 heads aren't the way to go. Especially with mild cams and CR. I'm sure if you cranked up the cr and duration we'd be surprised the hp out stock 318 heads but most are gonna be lucky to break 300 hp. And if you got the ability to port a set of heads you probably don't need to be asking how to make 300-425 hp.