Technically, there is no neck and bridge Blackout. They are ceramic and alnico magnet Blackouts, just like the EMG 81 and 85, respectively. It is simply common to put the alnico in the neck and the ceramic in the bridge, since the ceramic has more output and more grind.
If you only put a pickup in the bridge, how did you wire it? Sorry if this seems insulting, but did you use a stereo jack, 25K pots, and a fresh battery?