I also have a mex tele and had the same problem i think that you have. I tried fitting a jb junior to the neck pickup and found that whilst it fitted it sounded crap -worse than before!

I stuck with the jb and found that cutting f-holes in the body of the guitar using a key ring pen knife and the rough edge of a 2p coin made the guitar sound amazing. Make sure that your holes are big enough and will have a much lighter guitar with a sound similar to an ibanez jem!