there are 2 Ferodo DS2500 pads available for the 172/182 part numbers are 406H and 565H
the 406H is a thiner pad and has less overall surface area, below are images of both, you can see with you own eyes the difference in surface area! (not forgetting the actual thickness of the 406H pad is less too!)
406H
565H
note both pads need the back plate filing down and the shims need to be removed from the pad carrier to avoid any binding issues in future