I have no knowledge of 33 or Cobra brake configuration, maybe there is cause to be concerned.
On my 818 the default is the Subaru donor brakes. Option is a Wilwood kit which I have. A racer in OR has had brake issues and discovered the Wilwood upgrade has been listed incorrectly content for years. They list 1.25 thick rotors, 0.81 are supplied.
Looking at my car, the previous owner installed the 12.19 dia rotors in front (as I would) and they fit the pad radius perfectly.
The other two rotors are 12.0 diameter which fail to cover the rear pad radius by about 0.19. As I see it the larger rotors should be front and rear.
More troubling are the small pistons (1.0) in the rear and 1.62 in the front when the weight proportion favors rear. The proportioning valve is plumbed to the front(?).
Again the calipers should be closer or the same front and rear. I have lots of work fitting an alternative body and cooling system. I will get to brakes later.
jim

staggered shims.jpgstaggered shims2.jpg