Been working on daughter’s car (65)for some time. Finally got all the bugs worked out and she idles great ( high but smooth). I attempted to reduce the idle speed from roughly 1100 to 750. The lowest I could get it was 900- 925. Looked around on web and found a video that kind of related to my issue. In it he talked about the engine sizes. I got the casting info from the engine which when decoded indicates that at least the head came from a 69 Falcon. The video also discussed the size...

65 carb confusion