318 , 340 shares the same oil pan and external dimensions as 273. Without looking at casting numbers no way to tell the difference. Is a 340 in place of a 273 stealthy?
So if you want to stroke a 273 and keep it looking stock that is great. But the interesting aspect is the modifications done to give the underdog the edge. So then the stealth side of things is not as interesting.
That's the way my simple mind looks at it. If ya like the 273 small bore use it. If you can make the smaller bore with high compression work that's a bonus. If everyone thought the same things would get old quick.