Originally Posted by The HACK
If you mean take the existing front OEM caliper and use it in the rear, the answer is a simple NO. First you would have to custom fabricate a bracket to fit the much larger caliper to the rear. Second, that rear caliper now will have significantly increased in size of piston and therefore completely f**k up your front/rear balance AND totally screw up your master cylinder to slave size ratio.
It won't work. The only reason(s) why most front only kit works, is that the overall surface area of the multiple pistons are no larger than the factory single piston size, so the brake proportioning remains the same while brake torque, heat capacity and dissipation has increased thus improving overall efficiency.
Thanks. That is what I suspected. But I think you misunderstood one thing...although I think the answer will likely be the same. What I was getting at is to put on a BBK to the fronts (355mm or similar) with calipers and everything then move the stock front caliper to the rear with the 345 mm stock size front rotor. Most BBK sold for the rear are 345 mm rotors (same as stock fronts size) and designed to work with 355mm front rotors and stock master cylinder. This was why I was asking the question. I suspect the answer is the same because of the braket you mention but not sure why this situation would drastically upset the brake bias since the front is still larger than the rear and bias would remain "relatively" unchanged and in fact should be the same as BBK in front as well as rear.