I learnt the hard way
Ferodo brakepads part number FDB277P advertised to fit front brake pads for an RH. Well they dont fit, they appear to have the right shape but at 10mm thick they wont fit, not to mention some heavy filing of the backing plate to get the pin to line up
Same goes for Ferodo FDB177P to fit rear RH and Standard brakes.
Make sure pads are only 8.5mm thick