Larger pads you say...
Porsche / Q7 18z pad vs S8 Brembo! These things are huge
Tbh I should have figured that out from the size of the caliper but it didn't really register until I had them in my hand.
Btw, cheapest brake pads on the market for a Porsche Cayenne / Audi Q7? £26
For reference, this is the 18z caliper on an S8 Brembo upright - no way this will work:
This is the 18z caliper on the S8 345mm disc - also not going to work
However, the pads fit the D3 360mm disc perfectly. The only challenge then is a 4mm offset in the mounting holes:
I think this might be possible to solve by boring out both the caliper and the upright an additional 1mm and creating an offset bushing to take an M12 12.9 bolt, something like this:
I'd have a plain one in the caliper, and the threaded one in the upright, both knurled slightly to grip the aluminium and not rotate, then they'd hold everything in place nicely. I did this many years ago to get Nissan Skyline 4-pots caliper on my Corrado
However with this setup, its a compromise between using M12 12.9 hardware vs OE M14 10.9 hardware or removing sufficient material from the caliper to get M14 hardware in without losing strength.