Looking to upgrade my '57 Buick from single res M/C without power to dual M/C with booster. I have drums all around. Discussing this with a friend he did the same process with a problem that cropped up. Apparently he installed the booster without checking what the PSI output would be. According to him the PSI of the front brakes was about 10 and the rear was about 2. This apparently caused the front brakes to eventually lock up. Antbody have any hints/advice/experiences for me?