I've seen several cars that have torn at the brake master cylinder mount...
You definitely need an inner reinforcement plate after the damage is repaired. I'd also consider running a tubular brace in the engine compartment from the Master cylinder/clutch area forward to the shock tower. IIRC, it was "roadracer" (aka Charlie Jones) who built one of those after observing quite a bit of firewall flex on his car - said it tightened up the braking quite a bit. I'll see if I still have some pictures.
I once did the same thing with a 77 Chevy Monza V8/4-speed. Kept eating clutches so we put a HEAVY duty clutch in. Promptly pulled the clutch cable right thru the firewall. Drilled a hole in a 6x6 piece of 1/8" steel plate, put it together and sold the car... :wth
You definitely need an inner reinforcement plate after the damage is repaired. I'd also consider running a tubular brace in the engine compartment from the Master cylinder/clutch area forward to the shock tower. IIRC, it was "roadracer" (aka Charlie Jones) who built one of those after observing quite a bit of firewall flex on his car - said it tightened up the braking quite a bit. I'll see if I still have some pictures.
I once did the same thing with a 77 Chevy Monza V8/4-speed. Kept eating clutches so we put a HEAVY duty clutch in. Promptly pulled the clutch cable right thru the firewall. Drilled a hole in a 6x6 piece of 1/8" steel plate, put it together and sold the car... :wth