hunkychunky1

HI There ! I am trying to fit two dimarzio model j pickups into my fender jazz bass. I would like to use the dual sound capability of these p/ups and want to install new pots with the switching built in so i dont have to drill any new holes. What impedance pots should i use ? 250k or 500k i am confused are the model j humbuckers or single coil ? am i trying to coil tap a humbucker ? Any help or suggestions would be greatly appreciated. Thanks Hunkychunky!