QUOTE(Jeff Bowlsby @ Oct 21 2013, 08:56 PM)
Well there you go...the 19mm MC is a downgrade not an upgrade for a stock 914.
I doubt it to be either.
It is often misrepresented as an upgrade. It will not improve the braking but, it will improve the feel. It makes the pedal slightly firmer. So slight that I tend to doubt anyone would notice. It also requires more effort... again, so slight I doubt you would notice.
The price is better and they are readily available, not so much as of late with the stock 17mm which will set you back and additional $50 clams.
I "always" recommend an ATE 19mm when in need of a Master Cylinder.
It will change your fluid dynamics so I would suggest you simply re-bed the pads. Sanding is not needed unless you think you've glazed them.