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

For stock SBMs equipped with autos;
Measure out about 220 yards, then, step on the gas.
If watching grass grow is more exciting, that would be a 273 2bbl.
If you can measure how long it takes with a sundial,
it's a 273-4bbl or smog-era 318
If the car manages this in less than half a minute,
then it's an early hi-compression 318 or a 2bbl 360.
If you actually need a stopwatch, it's a 340, or a 4bbl 360.
If it burns both 295s all the way;
it's a 360 and a daymn fine one

Yes I'm kidding;
I gave the 273 far more credit than was due........ lol.