I put wilwood 4 wheel disc brakes on my 68 charger still using factory pedal. The brakes are for 15 inch wheels I can get the part number if needed. The master cylinder bore is 1 1/8, I have an 8inch dual booster. There is no way I can get the brakes to lock up the pedal is like standing on a brick, the car will stop but is not right. I'm thinking I need to go to a smaller bore, but what size options are 7/8, 15/16 or 1inch. Has anyone here dealt with this?