Page 8-72 of the 67 shop manual has the compensator pictured in the PCV hose. (figure 28) It is labeled as "non-thermactor A/C 289 (2-V) models only". Not sure if the 65 - 66 manuals have similar information, But I know some of the 4100 4-V carbs in 66 had built in compensator on rear of air horn. The 66 4100 carbs with compensator were for emissions equipped cars (California)
So apparently both A/C and or thermactor determined if compensator was present, but am unclear exactly how the rule was applied. AM curious if the 66 manual shows compensator in the PCV hose for 2-V carbs?