the SD Distortion is the perfect thrash pickup but it might be a little bright for ya
Indeed, the perfect, passive thrash pickup. If he comes from an EMG81, maybe the brightness isn't that bad.
Besides, in the wrong guitar, the JB has quite a screechy high-mid/top-end and with the Distortion it's just bright, but never screechy. Sure, in the right guitar the JB is almost like a desert island-pickup...
Also, when played clean, the JB (in series) is on the darker side. A Super Distortion from DiMarzio has a better useable (series) clean tone.
When coilsplitting, it's the other way around. JB=nice and with enough power and output. Super D=really bright, thin and low output.
When the SD Distortion is too bright, maybe the Dimarzio Evo2 or Norton would be a good call. They're still really tight with nice harmonics.
Original Evo was too bright for my tastes, but when I had a Duncan Distortion for a while, I loved it...just for thrash!