The factory specifications for the pickup height is 6/32" or 4.76mm from the top of the plastic between the pickup covers to the bottom of the G string. The angle of the pickup is set fairly level, so the larger strings are naturally a bit closer. If you haven't already adjusted the pickup or changed to a very heavy gauge string set, you shouldn't have to do any adjustments on the pickup.
On the new 2-pickup basses, the measurements are virtually the same on the bridge pickup and the neck pickup is further away, about 8/32" or 6.35mm from the string to the pickup.