Is there a simple/easy way to ID a 273 engine vs 318?

I'm looking at a '67 Windsor-built car that the VIN says had a 318 (which means it would have been a polysphere).

The current owner (who to me has an unknown level of familiarity with vintage Mopar mech/tech) says the car has a 273. Maybe someone told him that, and he doesn't know any better. I don't know.

I haven't been to the car, it's a bit of a drive for me.

Is there an easy way to know if it's a 273 vs 318? I have an LA318 in one of my cars and I know it's impossible to see any block stampings with the exhaust manifold in the way.

Here, this will help you...

https://www.forabodiesonly.com/mopar/ams/how-to-id-a-small-block-engine-block.35/

The last year of the poly 318 was 66...

The LA 318 began in 67...

https://www.forabodiesonly.com/mopar/ams/factory-v-8-engine-and-cam-specs-by-year-1965-1975.362/