Originally Posted by cdstl
Originally Posted by stumpy
I may be wrong but I though it had to do with what carb you have so you get the right size opening for the carb top.


The 383 sits higher than the 440 if I'm not mistaken.


you are mistaken
its the other way around
a 440 is a rb or raised block engine = lower aircleaner throat
a 383 is a b engine