Is building a stroked 318 better than a stroked 340/360?

Not bad at all! I think Steve Dulcich build a 318 with stock parts that made a little over 400 HP. But I believe he used magnum heads on that build.
He did 3 that I know of one with magnum heads one with ported 302 heads and one with older eq's then he ported the eq's for 425 hp. Think the cams were comp 280, xe268h, xe285h on 10 ish to 1.