John
I was reading this link on another forum. This guy is using the same carb as you. Also talks about d3ve heads.
http://www.ford-trucks.com/forums/15...d-of-dove.html
I have never heard about riuning your engine with an underpower carb. Alot of people went to smaller carbs during the 70's gas crisis! As for the unleaded vs. leaded issue, some of the guys with more experience will have to answer! My engine is a 71, and is running on unleaded! Steve.