Thanks for your thoughts guys, it may well be one of those mods where I have to give it a go and see. If I do run into issues, it's nothing a new set of wheels can't fix
For those who've done the
M5 rear caliper upgrade... Did you use a repair kit for the carrier and caliper i.e. replace the piston, seals, etc?
If so, did you use a repair kit for the 550i (seeing as the M5 and 550i share the same caliper)?
Reason I ask; I haven't been able to source an M5 rear brake repair kit, but can see 550i kits out there.