I have read so many threads where people on here say that 2x17670's will not fit in a g2 an14 combo. Now this is true, expect when you install an aftermarket switch such as the deal extreme 6p/g2 clicky and gut your switch and simply thread in the new clicky ( costs $3.50 by the way).
I absolutely love this set up. This will be my summer light for camping, bonfires, or whatever. I have 4 g2's and i still grab this one because i know the batteries aren't going to die on me.