I have a pair of GFS Bigmouth humbuckers that were just a little too hot for my tastes. The neck pickup was a bit muddy on the lower notes.
I already had the stock ceramic mags swapped out for A5 by a p/u winder friend of mine a while back and that helped alot.
I decided I would unwind them a bit to see if I could get something even more pleasing to my ear.
The GFS site says the bridge is 9.4K and the neck 8k however both mine were about 9.4k. I suspect that even though the neck p/u had a sticker on it saying "NECK' it was actually a bridge pickup that was mislabeled.
Fortunately they weren't too heavily potted when I opened them up so the unwinding was very easy.
I had my p'u maker friend disassemble the first one and get me started (I'd never actually looked under the hood of a humbucker before) and then I took them home and did the rest.
Well actually I've only got the bridge completely reassembled. I'll get the neck back together tomorrow.
I wanted the neck to read 7.9k and the bridge 8.5k.
Each coil from the bridge p/u had this much wire removed. I would take a bunch off and then take a reading to see where I was at.
One coil measured at 4.2k and the other at 4.3k.
They're going back in the guitar I just built after I get it painted so I won't get to hear them for a couple weeks or so. If they still aren't what I want I think I'll just get my buddy to re-wind them.
All in all it's been an enjoyable project and I've learned a heck of alot too.