I would assume all bulbs would fit all ballast? Ive gone through about 2 HID kits. First one a bulb crapped out on me. The company sent me a new one free of charge. That was a 35w system. ( Which most HID's are) The kit I have now is a digital 55w system. So its much brighter since I got smoked headlights.
anyway im gonna just buy some 55w 8500k bulbs tonite and ill let ya know how that turns out... hopefully i have its either a 55w kit or less cuz i dont think anything bad will happen if i put in bigger wat bulbs...