I don't see a 318 as an underdog necessarily, you look at a 400 hp 318 vs 360 it's similar parts, main difference is a 360 is gonna operate 3000/3500-6000 rpm stall to shift points and a 318 gonna need 500-700 rpms more, 3500/4000-6500+ rpm, requiring more stall gear less low rpm driveability, if those things are a non issue or maybe even desired. Then there's little reason not to build a 318, I see it more of a design issue than a capability one.