I recently picked up a Proform carb and have a question for guys that run them. Is there a special stud that they need for the air cleaner ? I've tried a couple different sizes but none seem to work. I've seen online a Proform adapter sleeve but can't seem to find anyone that still sells it - Summit site says no longer available. Anyone run one that has had luck a certain size / thread type ? Thanks. not sure if it matters, but I'm working with a Proform 750 Race Series.