Just a FYI as I went through this last month Unless something has changed, the SS calipers only work with the SS brackets. There is a bevel on one edge to compensate for the extra meat of the caliper.
EXT caliper above, SS below. Not sure what bolts they used for these EXT calipers but they went back regardless.
I purchased the brackets awhile ago, then the calipers, finally realized the brackets were incorrect.
