Help Identify Early 318 Single Plane Intake

Mike,
When was the last year of the 273 ?

Friend of mine was saying that the smaller exit ports on that single plane makes him think it came off 273. That would have to be 66 for it to be off 273, cause it bolts up to the 69-74 318s. What you think ???

Undersized ports big time:
View attachment 1715548975
273/318 ports are the same. 69 was the last year for the 273.