Man a friend told me about this website where they tell you how to do this, they turn a 8210/8250 or 8850 into a 8855.
I did not believe this! But i think it would work, it looks like a real ball breaker to do this but.....
Its on a chinesse site
www.shujuxian.com go to
www.altavista.com and use the translator (chinesse to english) and have a look on the site on the left side. Very interesting to read about this.