the carter webers were progressive 2 barrels. unlike a 4 barrel, it was not connected directly to the butterfly shaft. carbs are long gone but do remember it being a full 110 degrees to open both butterflies. neither butterfly turned 110 but the center pivot did. I made the discs just like yours, marked 0-180 and verified total degrees from idle to wot. the fulcrum and linkage to each butterfly was part of the carb and not easy to modify. they were less than $200 for the pair so I just jumped ship but not before making several sets of arms based of the original disc and each time, I verified it was a full 110.
