Unless you're downgrading to MK2, you shouldn't need a .pit for anything. If you're re-flashing stock via Odin, just put the tar.md5 in the AP tab and click 'Start'. Besides downgrading, I don't see why you would need a PIT file.
Anyways, best of luck!
---------- Post added at 02:12 AM ---------- Previous post was at 02:06 AM ----------
Lol, I forgot to post this, but- (I would take this with a grain of salt), I did some research, and I read that the partitions are the same on the I337 and I337M, so you just need to find the .pit for what your firmware would be on an I337. For example, if NE1 is 4.4.2 on the I337M, and NB1 is 4.4.2 on the I337, then you would need a NB1 .pit, or if you're wanting to downgrade to 4.3, find an MK2 .pit file.
Again, best of luck!