Going through a bit of a brake upgrade at the moment, the brakes on the car have been good but wanted to get rid of some weight. Got some AP calipers to go on the front but haven't got the brackets back from the CNC shop yet.
The standard rear calipers on a 105 are very heavy and they also suffer from shocking piston retraction due to poor seal design which leads to bad pedal feel. While scouring the internet for a suitable replacement I came across these Wilwood 4 piston ali calipers. Although they are 4 piston the effective area is identical to the original calipers, so brake bias will be the same, the pad area is much bigger so should get much more life from the pads and as a bonus the inlet port is in exactly the same spot!, so don't have to re-run any brake lines.
After a bit of CAD work I machined up a couple of ali adapter brackets and everything bolted up very neatly. The calipers where very good value for money so if all works well I might get a set of the brackets machined up if there's enough interest?