273, or 318?

A 273 is like a 289 Ford, why bother?

A 318 is a fine starting point for any build.

If your 273 has a steel crank then, stock 318 with trick pistons, if NOT.

I have several versions, a 110 overbore with turned down 340 pistons is one, (small bore 340@333cubes)

A 90 thou overbore with 360 turned down crank, with 360 flat top 1971 pistons is another, (360)

Or just get a 360 block for $50 and have a 408 stroker...

The choices are endless lol:rofl: