'41 Big Twin Air Cleaner

Up until now, I've been running the standard non-filtering air horn on my '41 ULH. I decided to switch to the optional '41 and up 7" round filtering air cleaner. But I'm unable to install the backing plate as the choke lever will not allow the backing plate to fit flush with the carburetor throat(M-51L). What gives?

The air cleaner requires the use of a different choke lever.

Bollix. Thanks Chris.