Toyota Man,
The grey Slot It motor pods are all the off set ones. The light grey pods are 1mm offset and require a special white crown gear that do not have any gear markings on them. The dark grey offset pods are .5mm offset and can be used with a regular colored crown gear.
The best thing to do with the white crown gears is to count them and write a number on them so you only have to do it once.
Marty