I know there is already 5 other threads on this subject but I still want an exact answer. I have a Mexican-made Fender Jazz Bass and I want to throw a set of DiMarzio Ultra Jazz pickups in it. Both pickups on my bass are the same size. Can somebody tell me whether I need to do any routing or anything like that or not. I want to know before I order the PU's. In one of the other threads somebody said that the MIM Jazz has two neck pickups. But I also saw a message saying that they are in fact two bridge pickups. And there was people saying that the neck hole is oversized, so no problem there but the bridge hole still needs some work. So, I need somebody who has done that conversion to tell me what what kind of issues there are related to it. I don't know if Ultra Jazz and Model J have the same size. I imagine they would. Better yet, can somebody tell me how big their Ultra Jazz pickups are? Thank guys.