I bought a set of Sudco filter adapters from Gregg Spears last winter, along with a set of K&N pod filters and never used either. I ended up going without any filters and using a screen to protect from larger debris. Info on the stuff:

Adapters are Sudco part number 021-216A, which will fit Keihin 35-41mm flatslide carbs, retail is $42 each (from Sudco's 2012 price sheet)

Filters are K&N part number RU-0800 (http://www.knfilters.com/search/prod...x?prod=RU-0800) and retail for $38 each. Best price I found on the web was $30 + shipping.

I mounted them last winter and took them off a week later. I never even ran the bike with the setup mounted. Sudco recommends using their o-ring to seal the adapter. Part number is 021-439 and they are $5 each. (not included)

Looking to get $75 for everything.