I was able to get my hands on a 1/2 pounder seymour duncan bridge pickup for my MIM Jazz, and I'm just curious of the difference between neck and bridge pickups, and if it would be fine if I placed it in the neck slot instead of the bridge (the store only had the bridge pup)? I have it in the bridge now but I want to aim for a tone based more around the sound of the neck pickup.
Fender makes their bridge pickup slightly longer than the neck pickup, so no, you can't put a bridge pickup in a neck slot, as far as I know.
^There's that. And it'll be voiced wrongly for the neck position anyway. Bridge pups are hotter than neck pups to keep their output, and hence their volume up. So if you did succeed in hammering a bridge pup into the neck slot, it would overwhelm whatever was in the bridge slot, and sound quite 'trebly' to boot.
If you want to route your bass and have more treble than John Entwistle, go for it.
I probably won't do it but to me, the pickup slots look the same size. I was reading on talkbass and people say that its the American Jazz that has different sized pickup slots, while the MIM has equal sized ones? Correct me if I'm wrong.