Ryan, are you talking straight Clouser's or the ones with the blade on the rear? If talking Clouser type flies, I use B10s. As big as I go is size 1 due to bucktail length. Even then I get more length because I then step up to the Half and Half Clouser. On what I am throwing for white bass I go with 4s.
If you are asking about Wrenche's wing ding blade in the rear I have never done that but am in the process.