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

The last year of the poly 318 was 66...
Semi-hemi (ie poly) 318 was available in 67 just not in A bodies.


Poly valve cover
Screenshot_20240106-144146.png


LA valve cover

Screenshot_20240106-144226.png


What to look for under the leading edge of the driver's side head. The leading letter is the model year C =67 D = 68 etc.

Screenshot_20240106-144410.png