I get the whole hub centric/wheel centric concept but I do have a question. Do you need to know the exact circumference of the hole in the wheel to order these? I guess I am wondering if the wheel hole is universal or does it vary?
I think your asking as if you have aftermarket wheels, how do the spacer people know what size that hub hole is so they can make a spacer for it...
The answer is, if that wheel is for a Nissan frontier, the hub hole should already be the correct size, the same size as the stock hub hole. If you have wheels that are not intended for a Nissan but still fit the bolt pattern, you should measure it and include that info on your order.
Is that what you were looking for?
Edit: 2nd gen hub bore size is 66.1mm