Were you looking for an 850 center squirter? That is the only carb I know of that has the same secondary linkage. I have one if you are.
I liked the 660 center squirters. I usually changed float bowls and modified the secondary linkage to allow more primary opening. I liked the way we tuned them using diffferent diameter wire strands to adjust idel mixture or actually changing the sizes of the pvcr on them by wiring them. Really good carbs at one time.
Ed