I recently finished a T56 conversion on my A4 GTA and noticed that when I push the clutch in the master cylinder flexes. It seems to tilt upwards. I'd say the rod deflects about half an inch. Is that normal? After driving it two weeks it seems to work fine but it still bothers me.

I'm using the 3rd gen pedals. However, I don't have the U-bolt through the master cylinder to firewall - just using two regular bolts. Maybe the Ubolt adds rigidity? Master cyl is brand new 4th gen master/slave cyl assembly.

There should be 2 braces that connect what should be the ends of the U-bolt to the large pivot bolt that goes through the pedals... without that, the firewall can simply bend away from the pedal bracket when you push on the pedal

RB83L69 speaks the truth. Past experience with the T-5/third gen pedals and clutch leads me to warn you that failure of your clutch master cylinder is also a likely possibility if the braces are not installed immediately.

I may need to replace my master cylinder. Just looking at component placement, will this job be as painful as the visual impression it leaves?

I have the braces. They shift a little, too. Especially the one on the left.