I've got a '75 J-10 with 4 wheel drums and I was wondering what kind of modification was needed if any to mount the booster and master cylinder to the firewall. I should mention that I have a donor 76 j-10 with the power boosted disc/drum set up that i was going to salvage for the parts. What is this aluminum booster adapter I keep seeing popping up in other threads? Will my stock pedal assembly work with the swap also?