Sagging master cylinder

[jfnar]

I'm trying to finish up my disc brake upgrade on my 68 gmc but keep running into challenges. I found yesterday that the booster is very close to the holly 4 bbl carb on the 292. My brand new 10" air cleaner will interfere and I'll have to modify the throttle linkage. I have a plan for those issues. Next I noticed that the booster/master cylinder assembly is sloping down toward the front. I don't know if that causes any problems with the functionality but I would prefer for it to be level. Should I shim the mounting bolts at the firewall to level it up? Any other suggestions? Thanks.