What cam would you run?
I think you might just get away with it. Your looking at .20 to get where you want to be. Your converters flash is 4400? You say? Also perhaps a on h drop in tire diameter for a little more finish line rpm?
Since a converter is pricey, even if it sent to be adjusted by the manufacturer for less money than new, try the other things first before the converter comes out. Figure that can wait until winter.
Everything else can be done sooner.