I have just swapped out a rather problematic autolite 4300 for a 4100 on my 351m. Everything works great with the exception of the transmission kickdown, mainly because there isn't any provision for such a thing on the carb. It is a rather early 4100, the numbers indicate 1961. I don't know if it was from a manual tranny car or not, but either way I need to fix something up. Has anyone on here dealt this before? Or am I the only one who doesn't just throw an edelbrock on everything?

 

You might be able to switch out the throttle shaft with the kick down hardware if the butterflies are the same or maybe just the kick down hardware