wheel size question (center bore hole size)

[centuryhouse]

Regarding 'bore diameter'.

I have a 72 GMC Sierra Grande. The wheels have been changed out to be 16" 5x5".

I want to order replacement wheels today but I don't have the truck with me. When I measured the hole in the center I believe it was 3". The replacement wheels I am finding show the center hole to be 82 or 83 mm (which is 3.25").

What are the standard center bore sizes for these? And does it matter? I can't think of what might go into the hole from the axle / rear end...?


Here is an example (ignore the obvious typo in the header, it is 8" not 18"):

http://www.amazon.com/dp/B004IK99R8/ref=wl_it_dp_o...