There are no differenses in dimensions between the 2 bearings

Maybe you have a wrong head or the information is wrong.

An old topic of me.
https://www.rctech.net/forum/onroad-...gs-virtus.html

You must see it on the old bearing that the inner ring is at one side smaller than the outside ring, or else you can see it in the crankcase that around the hole there is a dam.



If that is the case you need bearing 16006