Here is my W-MO 2-66 Group I/II R Model radiator. This differs from the 65 Galaxie radiator in that it is 1 1/2" shorter in height. It also has the R Model oil cooler mounted.
When I made the tabs , I used only single bolts on the tab to radiator support. I didn't want the extra set of holes and I also didn't trim the radiator support in front of the radiator in the event I choose to return the stock radiator.
Cheers,
~Earl J