I spent some computer time looking if anyone built these... NADA........
I dealt with this many years ago when I installed a hydraulic clutch in my 41 Chevy coupe (1971 ish) when these were not readily available... If you can tie it in with some structure works best or the entire plate you build/install will flex..... At least this was my experience...
I ended up with a L shaped angle piece bolted to the top of the firewall and pushing on the far edge of the clutch master cylinder.. It was ugly but prevented the intire pedal/master cylinder/firewall from flexing the firewall each time the pedals were pushed on.......
I dealt with this many years ago when I installed a hydraulic clutch in my 41 Chevy coupe (1971 ish) when these were not readily available... If you can tie it in with some structure works best or the entire plate you build/install will flex..... At least this was my experience...
I ended up with a L shaped angle piece bolted to the top of the firewall and pushing on the far edge of the clutch master cylinder.. It was ugly but prevented the intire pedal/master cylinder/firewall from flexing the firewall each time the pedals were pushed on.......
One thing I’ve noticed on Ford, when they use a doubler on the firewall to reduce flex, is that the doubler is generally a thicker metal than the firewall and the Engels of the doubler are rolled, to reduce the ability for it to flex. Here is a bad picture of my 73 with the doubler for the brake booster/master cylinder. If you look closely, you can see the rolled top edge of it. Steve
Best way to brace it is from the inside but not many want to pull a dashto plate the firewall in that area.