I bought a front disc brake conversion kit for my 69 Charger with manual brakes from Stainless Steel. I've bled the system and the pedal is firm. The proportioning valve that came with the kit has been adjusted both ways which doesn't seem to help and it's located between the distribution block and rear brakes as per the instructions. I've cleaned the discs with brake cleaner. When I apply the brakes really hard the car just gradually slows down and eventually stops. The pedal only moves about and inch or so and is firm when I do this. At walking speed I stand on them hard and again is just barely works instead of stopping the car. My 10" drums worked way better! Any ideas or has anybody had this problem before?