273 Performance build possibilities.

One thing to keep in mind is, for street type builds, for the most part, a given level of “rowdiness” will get you to certain hp/ci level.
This won’t change very much with different displacements.
So, if you built an engine that’s 1.15hp/ci……. That’s roughly 315hp out of a 273, 365hp from a 318, or 410hp from a 360.

The 400hp+ 360 will be easier(and likely cheaper) to build than the 315hp 273.

It just depends on what you’re looking for.