if it's the valve causing the issues then a different brake booster will make no difference unless the valve itself is put back the correct way. It kind of makes sense, the one way valve is there so the vacuum on the brake booter is maintained from the engine, if the valve is the wrong way around then that line is doing nothing as it's effectively been blocked. It will always be at atmospheric pressure and increases, pressurising the entire system, hence why the pedal goes so hard. The booster itself is fine, it's the way it has been plumbed together which is the problem.