I thought these were pretty heavy too.
See David Schwabs comments on this old thread
http://music-electronics-forum.com/t3162/
That would be me!
What's going on here is this Gotoh pickup is wound with very heavy gauge wire, so it's really a low impedance pickup. I'm not sure why they would do that, but I had heard that the early Gibson or Epi (I forget which) reissues had these 2K pickups. This made me think they were doing this because of the reissue LP Signature (Jack Casady) bass using the same gauge wire. I guess they wanted a cleaner tone out of it.
I have a 70s EB-0 pickup that I had rewound to about 12K. I had it in my '73 Ric, and it over powered the bridge pickup. Rewound it still had a similar tone, but was a little more open sounding. It wasn't super bright though. My pickup read about 30K before I rewound it, as did the pickup in the EB2D I used to own.
The real Mudbucker is wound with standard 42 AWG wire, and has a whole truckload on each coil. You can have that one rewound, but it would be more expensive than the Mudbucker sold at
www.guitarpartsresource.com, which is listed at 29k.