I asked the same question on your website,
Can you just swap the crystal to 14 or 16 and nothing else and get increased results?
A good rule in life is: No, you can't get something for nothing. There is always a catch.
In this case you risk destroying your miner quickly, or possibly reducing its life. As the number of people who've tried changing the oscillators can be counted on one hand, we have no idea how long these modified units can run for. YMMV.
Wow and with all that you didn't answer my question.