A lot items that are not is stock can be ordered by VIParts at the suppliers.
In general it takes a few days to receive those backordered items after an order is put on the webshop of VIParts and mostly will be shipped the same day when it’s deliverd to VIParts (Mo-Fr).
In few cases the supplier is also out of stock and information is provided to VIParts and passed on to you as a customer.
If you prefer to know the possible delivery time upfront before you order then you can always contact VIParts and I will get the information from my supplier (mostly given within one working day).