When I upgraded the brakes and master cylinder on my '08 Suzuki GSXR-750 track bike, I went with '08 and up brake cylinders from a Yamaha R6, and a '14 Master cylinder from an R1. One finger stopping with a set of the Vesrah XX pads and very linear too. I've hauled it down from 165 mph on the track with the greatest of ease.

 

Did you upgrade the rotors as well?

Sent from my Moto Z (2) using Tapatalk

 

Does one of the masters take up less space on the bar? Do they both use the same banjo fitting? do you prefer one over the other, why? will one be easier to cram against the switch housing, or mod to do so.
Heres a picture of how close I need to mount the master, I dremmeled out a pocket for the switch gear housing wires:

 

I honestly couldn't tell you about if there is a size difference between the R6 and the R1 master....it wasn't an issue for my application so I didn't look into it. As far as I know, the banjo bolts are the same size, but of course you would need one made for a double hook up if you are going from one line to two lines. I went with the 2014 R1 master as it is made by Brembo for the Yamaha. and had the bore diameter that I needed for my application.

 

Thanks Triplethreat,
I went with the '14 ,R1 master.