I had mine snap on me too after about a year and half of heavy daily driving. Here's what i did:
I simply bolted a home depot metal angle to the top of the bracket and braced it against the dash frame rail. This help brace against moment force on the bracket.
I also made this spacer to go between the master cylinder and firewall to tweak the location of the pedal so it wasn't so high.
Let me use fewer washers. Actually think i was able to set the bracket directly on the firewall with no washers. Been so long i don't remember.

I simply bolted a home depot metal angle to the top of the bracket and braced it against the dash frame rail. This help brace against moment force on the bracket.
I also made this spacer to go between the master cylinder and firewall to tweak the location of the pedal so it wasn't so high.

Let me use fewer washers. Actually think i was able to set the bracket directly on the firewall with no washers. Been so long i don't remember.