Stock brake booster support ?
 

While adjusting my brake pedal rod to the power b. linkage and new booster. I notice the master cylinder moving about 1/2 " to the side when pushing on the pedal.
I saw this through the windshield with the hood up. The flex is coming from the firewall.
I'm also running a master cyl. from a '71 chevy for its disc-drums app.
My ?, Is that normal or Is there a support bracket I'm missing.
Thanks , D.

Re: Stock brake booster support ?
 

If you are using a brake booster that is attached other than thru the original bolt holes, that will explain the movement. Your booster is not securely attached to the pedal assembly bracket.